IMAP SERVICE PROVIDERS
A Step in Dealing with
Viruses, Spam, and Email Overload

Meta Notes

Note about the ordering of these terms: The terms listed earlier are used in the definitions of later terms.

individual account or personal account or single-user account

A customer of a service provider with a single user.

group account or family account or business account or reseller account or multi-user account

A customer of a service provider with multiple users.

user or login or user account or account

A person with her own username, login ID, password, email address, IMAP-accessible mailstore, and possibly server-side file (non-mailbox) storage. Important: A user is not the same as an email address because on many systems it is possible for a single user to have multiple email addresses (see the definitions of email alias and subaddress below). Note: The word account is ambiguous because it is sometimes used to mean multi-user account (defined in previous item).

username or account name

The sequence of characters that identifies a user on a particular system. Some systems have very restrictive limits on what a username can be, but a user can often get her desired email address by creating an email alias. For more about this, see While Signing Up: Choosing Your Username, Password, Domain Name, Aliases, and More below.

login ID or sign-in ID

The sequence of characters that is used to log in to a system. Sometimes the login ID is a user's username, sometimes it is a user's primary email address on the system, and sometimes it is something else. Some IMAP servers, for example imap.cyrusoft.com, allow anonymous logins. Note: On some systems, the IMAP server and the outgoing SMTP server use different login IDs.

administrative user or administrator or admin or master user

A person who can edit the global configuration for an account. This might include adding & deleting users, creating & deleting shared and public mailboxes, setting ACLs (access control lists), maintaining shared LDAP address books, maintaining shared greenlists, setting the default “skin” of the webmail client, and specifying SMTP-level filtering for a domain (blocklists, greylisting, SPF policy, etc.). Note: On some systems, the person who is the administrative user has two login IDs, one for configuring the system & managing her users, and one for doing email and other regular-user activities.

INBOX

A user's default incoming mailbox on a particular IMAP server. The string INBOX is case-insensitive, but it is often written in upper-case letters because that is how it is written in the IMAP specification (RFC 3501). [Geek Note: If you have shell access to your IMAP server, you might discover that there is no mailbox named INBOX. This is because INBOX is a nickname or abstraction and the IMAP protocol translates the special name INBOX to the actual default incoming mailbox name on that particular IMAP server. Examples of actual default incoming mailboxes include /var/spool/mail/username, /var/spool/imap/user/username, and $HOME/Maildir ]

mailbox or box or mail folder or folder

A container of messages. INBOX, Drafts, MaybeSpam, and Sent (which is sometimes called Sent Items, Sent Messages, sent-mail, or sentmail) are examples of mailboxes. Note 1: The word folder is ambiguous because it is sometimes used to mean directory (defined below). Note 2: In the POP world each user account has only one remote mailbox, namely the default incoming mailbox or INBOX, but in the IMAP world a single user account will usually have multiple remote mailboxes (this is one of the advantages of IMAP over POP).

sub-mailbox or subfolder

In a user's personal mailbox space, a mailbox which is not the INBOX is sometimes called a sub-mailbox. Note: The word sub-mailbox is misleading because it is possible to set up some IMAP clients so that a user's mailboxes are presented as a flat non-hierarchical structure, i.e., with no mailbox that is “under” or “sub” or “a child of” another mailbox.

local mailbox or local mail folder or local folder

A mailbox that is not accessed using IMAP, but instead is accessed using local file system calls. Contrast this with a remote, aka IMAP-accessible, mailbox. Note: A local mailbox is often in a location or in a (possibly proprietary) format that is readable only by the mail client that created it.

directory or hierarchy or folder

A container of mailboxes and possibly other directories (subdirectories or child directories). Directories can be used to create a “mailbox tree” or “mailbox hierarchy.” For example, I store my solicited-bulk-email boxes in a directory named SBE. There is no standard IMAP hierarchy separator (delimiter), but most IMAP servers use either slash (/), dot (.), or backslash (\). Note: The word folder is ambiguous because it is sometimes used to mean mailbox (defined in the previous three items).

dual-use name or dual-use mailbox or dual-use mail folder or dual-use folder or hybrid folder

A container of both mailboxes and messages, i.e., a dual-use name is both a directory (defined in previous item) and a mailbox (a container of messages). For example, on a Courier IMAP server, INBOX is both a container of messages and a container of all of a user's personal mailboxes (other than the INBOX mailbox itself, of course). Note: Some IMAP clients need to be told whether an IMAP server does or does not support dual-use names. For example, in SeaMonkey Suite and Thunderbird, a user needs to check or uncheck the checkbox labeled Server supports folders that contain sub-folders and messages. In Pine, if you access an IMAP server that supports dual-use names, it is useful to set separate-folder-and-directory-entries or quell-empty-directories. [Geek Note: Contrast dual-use name with no-inferiors name and no-select name, which are the mailbox and directory types used by UW IMAP when the underlying mailbox format is either mbox or c-client MBX.]

cabinet or virtual collection or virtual directory or virtual hierarchy

A list of mailboxes that are presented as a single directory, but in fact might include mailboxes from multiple directories and multiple IMAP servers. Mulberry uses the word cabinet and Pine uses the phrase pseudo collection and the word view for this. Many IMAP clients support the special “Subscribed” cabinet, which is defined in the next item.

“Subscribed” cabinet or “Subscribed” virtual collection or “Subscribed” virtual directory or “Subscribed” virtual hierarchy or “Subscribed” namespace

A list of mailboxes that a user has subscribed to using the IMAP subscription mechanism. A user's list of subscribed mailboxes for a particular IMAP server is usually stored on that IMAP server and is thus available to all IMAP clients (both desktop and web-based) that support IMAP subscriptions. Note: Some IMAP clients, for example Mail.app and Pine, do not support IMAP subscriptions.

virtual mailbox or smart mailbox or saved search

A list of messages that are presented as a single mailbox, but in fact might be a subset of the messages in a mailbox or include messages from multiple mailboxes. A virtual mailbox allows you to zoom in on the messages you are interested in. For example, all messages with a particular keyword (label), all messages from a particular email address, or all messages you sent & received during a particular time period. Also see Sometimes a Mailbox is Just Not a Mailbox at Deflexion.com and Universal Inbox at the WebSeitz WikiLog.

personal mailstore or personal message store or personal mailbox space or personal folder space or personal mail repository

The collection of all of a user's personal mailboxes, including the user's INBOX, on a particular system. To see a diagram of a personal mailstore and its relation to a mail user agent (MUA), see the 2005-May-26 message I posted to comp.mail.imap. Note: Some providers use the single word mailbox to refer to a user's entire personal mailbox space — this is very confusing if you are familiar with standard IMAP terminology (see the diagram at the beginning of this section and the definition of mailbox above).

personal file storage

Disk space that is used to store a user's non-mailbox data. For example, files that a user sends or receives as email attachments when using a provider's web-based IMAP client.

IMAP path or IMAP root or IMAP root path or IMAP prefix or IMAP namespace

The path to the location of mailboxes of interest. An IMAP path is used when specifying a directory or hierarchy (defined above). Here are some examples.

                                         sample        relative path        full path
IMAP server                 Login        IMAP path     to sample mailbox    to sample mailbox			
========================    =========    ==========    =================    ======================
default Cyrus or Courier    username     INBOX.        2do                  INBOX.2do
default Cyrus or Courier    username     INBOX.        SBE.webdesign-l      INBOX.SBE.webdesign-l
default Cyrus or Courier    username     INBOX.SBE.    webdesign-l          INBOX.SBE.webdesign-l
default Binc                username     INBOX/        2do                  INBOX/2do
University of Washington    username     ~/mail/       2do                  ~/mail/2do
dovecot.org                 anonymous                  dovecot              dovecot
imap.cyrusoft.com           anonymous                  mulberry.discuss     mulberry.discuss
imap.cyrusoft.com           anonymous                  lists.info-cyrus     lists.info-cyrus
imap.cyrusoft.com           anonymous    lists.        info-cyrus           lists.info-cyrus
ftp.cac.washington.edu      anonymous    #ftp/         imap/imap_archive    #ftp/imap/imap_archive

As you can see in the 6th, 7th, and 8th examples above, blank (i.e., nothing) is a possible value for IMAP path. Note: INBOX, ~, and #ftp are nicknames or abstractions and their actual locations on the IMAP server 1] depend on how the IMAP server is configured and 2] are hidden from — and are irrelevant to — a regular user of an IMAP client. See Also: RFC 2342 - IMAP4 Namespace, Folder Namespaces section of the Pine Technical Notes, the Courier FAQ, and Namespace (computer science) at .

email alias

An alternate email address that can be used to send email to a user.  Tips: To be able to send mail From an alias, use both a mail user agent and an outgoing SMTP server that allow you to use multiple roles (aka personalities or identities), i.e., allow you to send “forged” mail. To be able to filter incoming email based on which alias was the recipient, choose a mail hosting provider that injects a mail header line that records the original envelope recipient address. Also see the definition of subaddress in the next item.

subaddress or plus address or user-extension address or detailed address

An email address that can be used to send mail directly to a mailbox (that already exists) in a user's mailstore. If a user's address is user@example.com, a subaddress is usually of the form user+mailbox@example.com or user-mailbox@example.com. If the target mailbox does not exist, some — but not all — systems will deliver the message to the user's INBOX. Subaddresses are especially useful for signing up for mailing lists, transactional services (banking, shopping, etc.), RSS-to-email services, or any service where you want to be able to easily track (and possibly filter or reject) email from a particular entity. There is more information about subaddressing below.

MX hosting or domain hosting or virtual domain hosting or vanity domain hosting

The option to point the DNS MX record of your domain (or subdomain) at your email service provider's incoming mail exchange (MX) server. MX hosting is essential if you want 1) to have robust SMTP-level spam filtering for your domain's incoming email and 2) to avoid the problems with forwarding.  Tip: Some IMAP providers offer both email and web domain hosting, but I recommend that you get an IMAP provider whose focus is email hosting and host your domain's web site (e.g., DNS A record) with a provider whose focus is web hosting.

catchall alias or catchall address

An email address that catches all the email for a domain that was not directed to an existing user in the domain. Because of spam, I recommend that you turn off the catchall alias for your domain(s). Make sure that you get a provider that rejects catchall mail at the SMTP-level with a “user unknown” message so that legitimate correspondents will know that they need to use a different address. Note: AFAICT the only reason to use a catchall address is if you have promiscuously given out addresses in your domain and you've forgotten what those addresses are.

reject address or reject alias or negative alias

Some providers, such as Tuffmail, let you specify specific “reject addresses” that will be rejected (refused) at the SMTP-level with a “user unknown” or other permanent (5xx) DSN error message. Reject addresses are useful if you use a catchall address, subaddresses, disposable email addresses, or if you want to be able to send one-way outgoing-only announcements and use a no-reply From: header (for example, From: no-reply@your.domain, From: do.not.reply@your.domain, or From: bitbucket@your.domain). Important: Rejects or “bounce backs” should be done only at the SMTP level and I suggest that you boycott any provider or product that encourages users to do it after the SMTP handshake. Details about the problems with fake bounces are in this section of the Procmail Quick Start.

SMTP or Simple Mail Transfer Protocol

SMTP is the protocol that is used to relay mail from one computer to another computer on the Internet. All IMAP service providers offer incoming (receiving) SMTP service so that they can receive their users' incoming mail. However, some IMAP service providers offer outgoing (sending) SMTP service only when a user is using the provider's web-based IMAP client. With this type of IMAP provider, a user needs to use another outgoing SMTP server when sending mail from a local (desktop-based) IMAP client (for example, the user could use the SMTP server provided by the user's Internet access provider). If I write that a provider includes SMTP service in The Table or The List below, I am referring to outgoing SMTP service (because incoming SMTP service is always included). Also see SMTP at . Important Warning: Make sure your outgoing SMTP server has an rDNS record (defined below), has an IP address that is static (rather than dynamic), and is not an open relay. Otherwise your outgoing mail will be considered spammy.

SMTP path

The sequence of computers that an email message goes (“hops”) through in getting from the originating computer to the final receiving computer. Each computer on this path is usually recorded in a Received header line in the message. Note 1: Some computers on this path may not be SMTP servers. For example, the originating computer is often a simple desktop computer and not an SMTP server. Note 2: The target receiving SMTP server(s) for a domain name is specified in the DNS MX record for that domain name (see the definition of MX hosting above). Note 3: It is easy to forge a Received header line and spammers and other bad guys often do. Also see this 2005-July-22 article at NewScientist.com.

rDNS record or reverse DNS record or PTR record

If a numeric IP address can be translated to a host name or domain name, it is said to have a “reverse DNS record” or “rDNS record” or “PTR record.” Some SMTP servers, for example AOL, will accept email from a sending SMTP server only if it has an accurate rDNS record. See Also: 'Reverse lookup' at , RFC 1912, and man host.

Tip: To ensure that your outgoing email is not refused or considered spammy by a receiving SMTP server that does rDNS lookups, first use Verify Connecting IP to determine your ultimate sending SMTP server's IP address and then use Reverse DNS Check to check that your ultimate sending SMTP server has an accurate rDNS record. (These web-based tools are provided by AOL, but they are useful for troubleshooting general non-AOL-specific SMTP issues.) In other words, make sure that outgoing SMTP 2 in the SMTP path below has an rDNS record.

originating computer -> outgoing SMTP 1 -> outgoing SMTP 2 --> receiving SMTP 3 -> recipient's mailbox
                                           ^^^^^^^^^^^^^^^  ^  ^^^^^^^^^^^^^^^^
                                           ultimate sending |   MX server for
                                             SMTP server    |    recipient's 
                                                            |    domain name
                                                            |	
                                                            |	
                                                        "last hop"

See Also

• Power Pine: Terminology, which discusses the IMAP terms RECENT, SEEN, and UNSEEN.
  
  
• Procmail Quick Start: Terms Used in This Article, which discusses a lot of email terminology including MUA (mail user agent), MSA (mail submission agent), MTA (mail transport agent), and LDA (local delivery agent).
  
  
• Stopping Spam Creating a Stronger, Safer Internet: Glossary (according to this, John R. Levine wrote this Glossary)
  
  
• UW IMAP Frequently Asked Questions (FAQs), especially 1.8, 1.9, 1.10, and 1.11 What is the difference between "mailbox" and "folder"?
  
  
• comp.mail.imap:
  • 2005 April 21: Re: Please clear my doubts in IMAP by Mark Crispin, which discusses the terms mailbox, folder, and mailstore.
    
    
  • 2000 August 23: Terminology: folder, mailbox (Was: IMAP server: Sub folders) by Nancy McGough (that's me), in which I say:

    “We need a term that will give people a picture that they can keep in their head about what's going on without limiting their ability to take advantage of the features of different message storage structures.”

Tools for IMAP Users

What to Look for in an IMAP Client

What to look for in an IMAP client is discussed in

• The University of Michigan's IMAP4 Client Evaluation Criteria
• EmailDiscussions.com > Discussions about Email Services > Email Help Needed! > The Ultimate Mail Client

For me, it's essential that an IMAP client supports secure authentication methods, has the ability to flag (label) IMAP-accessible messages, has powerful sorting and searching options (including full text searching), makes it easy to move messages to any mailbox on any IMAP server (including moving to a mailbox that does not yet exist), lets you open more than one mailbox at the same time, and has the option to store configuration settings and address books remotely (e.g., on an IMAP, LDAP, or IMSP server).

Pine: Desktop- and Web-Based POP, IMAP, NNTP, & ESMTP Client

Even if Pine is not your primary IMAP client, it is a useful backup IMAP client because it has a small footprint, is surprisingly powerful and feature-rich, runs on many platforms, adheres to standards, and is available gratis (free of charge). There are more reasons why Pine is an Essential Companion to Other Mail Clients and Tools on the All About Pine page.

Setting Up Pine for Multiple IMAP Accounts

To set up Pine to access, manage, and search mailboxes on multiple IMAP accounts, you can use Pine's built-in configuration screens, which are available by typing MS (Main > Setup) in Pine, or you can directly edit your pinerc configuration file. It is cumbersome and confusing to edit the incoming-folders and folder-collections variables from within the Pine Configuration screens so I recommend that you do the following.

Exit Pine and make a backup copy of your pinerc file. Then open your pinerc using your favourite editor, such as vim or  pico -w  (the -w flag ensures that pico does not automatically insert any line breaks), and then

1. Add your INBOX specification at the service provider to your Pine incoming-folders list.
2. Add your mailstore specification at the service provider to your Pine folder-collections list.
3. Make sure that enable-incoming-folders is listed in your feature-list.

After you add these to your pinerc, restart Pine, type L to go to your Pine folder list, and read & manage these remote IMAP-accessible mailboxes.

Another way to go to a mailbox in Pine is to type  G (for GoTo) and enter the fully qualified IMAP specification of a mailbox, for example:    G {www.fastmail.fm/user=UID/ssl}INBOX

I have many more tips for using Pine on Infinite Ink's:

• All About Pine
• Changing Your From Header in Pine; especially useful is the Roles section
• Power Pine; especially useful are the sections:
  • Setting Up Local, IMAP, and NNTP Collections
  • Using the Incoming-Folders Collection (aka Pine Shortcuts)
  • Creating a PASSFILE for Storing Passwords
• Compartmentalizing and Sharing Your Pine Configuration
• Links to other Infinite Ink and world-wide Pine-related pages (sections of the All About Pine page)

Desktop IMAP Clients

In addition to Pine (previous section), there are many other clients that you can run on your desktop (or laptop) and use to access mailboxes on an IMAP server, including the following.

• The Mozilla project includes two IMAP clients: Mozilla Mail/News, which is part of the SeaMonkey Suite, and Mozilla Thunderbird, which is a stand-alone messaging client. Both are free (gratis and libre), open-source, and run on Mac, Unix, and MS Windows. For how to get around some of Mozilla's IMAP idiosyncracies, see Using IMAP with Mozilla and this thread at EmailDiscussions.com. If you want to help improve Mozilla's IMAP, see the MozIMAP forum, especially the message MozIMAP enhancement suggestions.
  
  See Also
  • comparison of SeaMonkey Suite & Thunderbird and Pine on my All About Pine page.
  •  my del.icio.us bookmarks related to Mozill are at del.icio.us/Deflexion.com/ under the following tags: Messaging/Clients/Thunderbird, Messaging/Clients/Moz, Moz/Extensions, and Browsers/Moz/Extensions (I need to consolidate these!)
  
  
  
  
• Microsoft Outlook, Outlook Express (OE), and Entourage all support IMAP but have problems, some of which are discussed in
  • Slipstick Systems: IMAP Accounts section of Internet Mail Issues with Microsoft Outlook
  • IMAP mailing-list message Re: OUTLOOK 2K+ your imap server closed the connection error message.
  • comp.mail.imap message Re: A good IMAP tutorial?
  Of these three Microsoft IMAP clients, OE is significantly better at IMAP than the other two.
  
  
  
• The premier GUI IMAP client, Mulberry, is powerful, robust, standards-compliant, runs on Linux, MS Windows, Mac OS, & Solaris, and was “designed from the ground up to take advantage of [IMAP].”
  
  See Also
  • Using FastMail.FM with Mulberry
  • comparison of Mulberry and Pine on the All About Pine page.
  •   my del.icio.us bookmarks tagged Mulberry and Messaging/Clients/Mulberry
  
  
  
  

The above is a list of the most popular desktop IMAP clients, but it is certainly not a complete list. Many more IMAP clients are listed and discussed at the links in Other Lists of IMAP Clients, which is in the section below the next section.

Web-Based IMAP Clients

In addition to WebAlpine and ssh-accessible Pine (described above), there are many other IMAP clients or gateways that are hosted on a server and can be used to access any IMAP-accessible mailbox, including:

• mail2web.com -- Web interface to any IMAP or POP accessible mailbox. Make sure you use the HTTPS secure login screen and choose the IMAP4 radio button. More than 14 million users. Also see their mail2wap.com service.  Question: Does anyone know if mail2web encrypts both the connection from your web browser to mail2web and the connection from mail2web to your IMAP server?
  
  
• xs2mail.com -- check your mail on any POP3 or IMAP account; free and premium accounts.
  
  
• e-mol.com -- Web interface to any IMAP or POP accessible mailbox. I don't think they support secure access, but please let me know if they do (or don't).
  
  
• n-ary's WebM@il
  
  
• mollymail.com
  
  
• Cyrusoft's SilkyMail is “the smoothest mail client in a browser” and has “the most complete IMAP capabilities available in a webmail client.”
  
  
• Minter Software's VisualMail can be set up to access external IMAP servers. Their VisualOffice also provides powerful anti-spam features (including TMDA), calendar functions, alerts & notifications, tasks management, bookmarks, file storage, and extensive customization options. MailSnare.net, which is described in The Table below, and the providers listed here offer VisualOffice.
  
  
• @Mail WebMail System -- “Users can choose to read email from any external POP3 / IMAP server on the Internet.”
  
  

Many service providers include a webmail client that you can use to access mailboxes that reside on their system. If you know of any provider that has a webmail client set up so that users can use it to access any — including external — IMAP-accessible mailboxes, please tell me.

More web-based IMAP clients are listed and discussed at the links in the next section.

Other Lists and Reviews of IMAP Clients

Each of the following discusses many IMAP clients.

• EmailDiscussions.com: Best email client for IMAP
• EmailDiscussions.com: IMAP under Outlook 2002 - IMAP mail clients in general
• IMAP Partners: IMAP clients -- “Covered here are the quirks, peculiarities, deficiencies, etc. of each individual client, with the aim of either helping you with the client of your choice or selecting a client.”
• SortOnce.com: IMAP email program configuration and usage guides
• webhostingtalk.com forum thread What's A Good E-mail Cilent For IMAP
• Comité Réseau des Universités (CRU) HTTP Mail User Agent Inventory - includes 55 entries, many of which support IMAP
• Robin Whittle's Email access via the Web – a listing of software
• The IMAP Connection: Products Supporting IMAP
• Wikipedia.org: List of email clients and Comparison of email clients

IMAP Servers

• imap.org: IMAP Products and Services
• Network Computing: Interactive Buyer's Guide: Mail On The Map: IMAP Messaging Solutions By Dan Backman, Internet Mail Servers Part ll (April 1, 2002) and this table

Miscellaneous IMAP Tools

• mailutil is a command-line utility that is distributed with the University of Wasington IMAP software and with both Unix- and PC-Pine 4.50 & later. It can check local and IMAP-accessible mailboxes for new messages; can copy or move a mailbox between two IMAP servers or between an IMAP Server and a local system; and can do a lot of other things.
  
  
• John Goerzen's OfflineIMAP -- A tool to provide IMAP support for mail readers that do not support IMAP (or support it poorly). Also, a tool to permit offline reading of mail. Provides full bi-directional synchronization of mail repositories. Provides a fault-tolerant synchronization protocol with full consideration of IMAP protocol. OfflineIMAP's multithreaded synchronization algorithm performs between 10 and 60 times faster than many mail readers' internal IMAP support and it can be used even with mail readers that support IMAP already. There are five available user interface modules, including scripted execution, an interactive terminal interface, and GUI interfaces.
  
  
• Roger Binns' IMAP Spam Begone (isbg) -- script that scans an IMAP mailbox for spam using SpamAssassin and moves spam to another mailbox.
  
  
• Lefteris Chatzibarbas's IMAPFilter.
  
  
• Pete Maclean's MailRelayer, which offers Internet remote access to email stored on PCs, and Maclean IMAP, an IMAP Server Engine for MS Windows.
  
  
• David Harris's Mercury Mail Transport System is a comprehensive mail server for Windows and NetWare networks that includes an IMAP server, a powerful content control management system for handling unwanted mail, support for external tasks such as virus scanning and archiving, fully-programmable automatic reply logic and much more.
  
  
• Toltec Connector is middleware that enables Microsoft Outlook to use an IMAP4 server while still using the functionality of the “Corporate or Workgroup” mode instead of “Internet Only” mode. This exciting product provides Microsoft Outlook with the ability to use an IMAP4 mailbox as an Outlook information store. This information store can hold any Outlook item and is not just limited to messages. You will now be able to share calendar information, individual folders and contacts with supported IMAP4 servers. Most of the IMAP4 servers are open source and runs on a variety of operating systems including Linux. This significantly reduces the total cost of ownership to the company.
  
  
• Bynari's InsightConnector for Outlook allows MS Outlook to use an IMAP server to store messages, calendar events, contacts and continue to be interoperable with MS Exchange Server. Note that this works via Bynari's “Insight Server" which is a package of Postfix + Cyrus + Apache + ProFTPd and a web-based management interface. Also see the article InsightConnector: Turning an IMAP Server into a Full Platform by Sue Mosher at Exchange & Outlook Administrator.
  
  
• Brighten Your Outlook—Rethink Exchange: Build a smarter, cost-effective IT environment with Steltor's Exchange Alternative.
  
  
• Kolab Project -- Free software groupware solution that uses Cyrus IMAP, Postfix, OpenLDAP, and the KDE PIM packages to store contacts, notes and calendar entries on the IMAP server.
  
  
• OpenGroupware.org (OGo) -- Open source groupware server to integrate with the leading open source office suite products and all the leading groupware clients running across all major platforms, and to provide access to all functionality and data through open XML-based interfaces and APIs. For more info, see the FAQ.
  
  
• I list many tools for Syncing and Slurping Mailboxes on the All About Pine page.
  
  
• I list many Email Notification Tools in the Procmail Quick Start.
  
  
• Search Freshmeat.net for IMAP projects.
  
  

Service Providers

Reasonably-Priced and Free IMAP Service Providers

What's in The Table

Some providers in the table provide a full range Internet services, including mail hosting, web hosting, Usenet news access, dial-in access, shell access, and more; some provide only mail hosting; most provide POP as well as IMAP access to messages; some provide a web-based mail client; some provide web-based tools for collecting messages from external accounts; some let users write their own Procmail or Sieve recipes. To find out details about a provider, follow the links to their site.

Default INBOX, Default Sent Mailbox, and Personal Mailstore Specifications

In the third column in The Table, I give the specification for the account's personal mailstore, the default “Sent” mailbox, and the default INBOX. These can be copied & pasted into your pinerc file, which is discussed above, or adapted for use in other mail clients. For many of these I have guessed the specifications based on information that I got from telnetting to the server (described below), and on what I know about how various IMAP servers are usually configured.

The specification for the personal mailstore is where your IMAP-accessible mailboxes, but not necessarily your primary INBOX, are stored. For Cyrus and Courier IMAP servers, a user's personal mailstore often resides under the “INBOX.” hierarchy and for a UW IMAP server, they often reside in a subdirectory of $HOME named mail or Mail.

    {imap.server.name/user=UID}#allfolders.INBOX.[] 
    

The /ssl, /tls, and /secure Qualifiers

In some of the specifications in The Table below, I use qualifiers within the squiggly brackets to ensure secure IMAP authentication. The /secure qualifier tells Pine to use CRAM-MD5 or another secure authentication method and /ssl and /tls tell Pine to encrypt the entire session, including the authentication. Details about these qualifier are in the comp.mail.pine thread about Questions about SSL, SASL, CRAM-MD5, etc.

The /tls (Transport Layer Security) qualifier is available in Pine 4.40 & higher; the /ssl (Secure Sockets Layer) qualifier is available in PC-Pine 4.20 & higher and Unix Pine 4.30 & higher. PC-Pine is pre-built with TLS/SSL support but Unix Pine needs to be built with TLS/SSL support.

If you use Mulberry as your IMAP client and want to be able to do secure authentication, you need to download and install the Mulberry crypto installer. The secure-authentication part of the crypto package is free (gratis), but the other part, which includes PGP, GPG, and S/MIME plug-ins, requires a payment of $4 (after a 30 day trial).

If I have left /ssl, /tls, or /secure out of a provider's specification below and it in fact works, please tell me. Also, if I put it in and it doesn't work, let me know that too!

^† Recommendation Icons

My primary goal in creating and maintaining this page is to find a good email and web hosting provider for myself. Back in the 1990s, I had such a provider, best.com, but they no longer exist and now, after much research, I have realized that 1) there will probably never again be a provider with such a great constellation of smart and talented people (e.g, Matt Dillon); and 2) it is now very hard to find a provider that is good at both email and web hosting.

For most people who are looking for robust managed email and web hosting, I recommend that you get (at least) two providers: one for email hosting and one for web hosting (*). The providers that I recommend are labeled as follows on this page.

		Mail-hosting provider that I recommend based on my research
		Web-hosting provider that I recommend based on my research
		Provider that I use and highly recommend
		Provider that I recommend you avoid (used mainly for providers who have lost users' email)

Note: There is currently no provider that I highly recommend (but I am always looking for such a provider!).

(*) For more about separating email and web hosting, see my blog item titled Use a Different Provider for Internet Access, Email Services, and Web Hosting.

^† How The Table is Ordered

Someone asked me about the ordering of the table, which I agree looks pretty random. Here's the algorithm I use to get the Sort key (first column).

1. lowest level account
2. one year pre-payment, including discount for annual payment
3. add setup fee
4. convert to US dollars (US $)
5. divide by number of megabytes of IMAP-accessible storage space

Free accounts all have a sort key of zero and are sorted by Storage Space, from highest to lowest. For the providers that have the same sort key (or the same storage space if they are free), I list the providers who send ads to their users at the bottom and the ones who support secure IMAP access or give Unix shell acess at the top. In the ideal world, I'd let you, the reader, change the sort key on the fly and I'd use two years rather than one so that the sort would more accurately represent providers who charge a one-time fee for extra storage space.

Of course, when you are choosing a provider, you should consider a lot of factors other than simply “Price per MB per Year.” See What to Look For in an IMAP Service Provider near the bottom of this page for other features that I think are important.

Translation and Conversion

• To translate a site, try Babel Fish or Google Language Tools or FreeTranslation or WorldLingo Online Translator or any of the tools mentioned in this Google Answers thread
• To convert a currency, try xe.com, ft.com, or oanda.com

THE TABLE

If you know the Pine incoming-folders, default-fcc, or folder-collections specification, amount of IMAP-accessible storage space, or fees at these or any other IMAP provider, please let me know and I'll include them on this page.

The List — 251 More Reasonably-Priced IMAP Service Providers

In addition to the more than 100 IMAP providers that I discuss in The Table above, this section lists a couple hundred more IMAP providers that I have not yet added to The Table.

1. 10tohost.com -- virus filtering, $2.00/10 MB/month
2. 1and1.com (aka 1und1.de) -- FAQ; “3.5 million customers on paid services”; injects the original envelope recipient in an Envelope-To header; backups but no customer-requested restores; also see this EMD thread
3. 4web-space.com -- I read in a discussion forum that they support IMAP, but I don't see this mentioned on their site
4. 65535.net / jvds.com -- cPanel
5. 852.net -- site is available in Chinese or English; located in Hong Kong
6. 9y.com -- 2 MB free, Premium Accounts, “Transparent, end-to-end 2048 bit encryption”; affiliated with Hushmail.com
7. accudomains.com -- Email account plans, domain name registrar
8. ace-host.net
9. actadivina.com Freeform and pre-designed packages -- Cyrus IMAP
10. addaction.net
11. affordablehost.com -- cPanel; Pre-Sales Q & A > Do you support IMAP?; supports SPF as of 2004 -Sep-14
12. aim.com -- free 2000 MB (will eventually offer unlimited storage), web-based client displays ads, announced 2005-May-12; also see this thread at EMD, this blog by an AOL employee, the aol.com listing below, and my AOL/AIM-related bookmarks at del.icio.us / Deflexion.com / HostingProviders / AOL
13. ald.net
14. aliencamel.com -- “Unlimited Email Storage” (might be a reason to Look OUT), Australian company; also see this EMD thread
15. all2all.org -- Twig webmail
16. aol.com and aol.co.uk (and many other countries) -- AOL's Open Mail Access, which includes access to their IMAP and SMTP (but not POP) servers using any mail client, made its world-wide debut on 2004 April 5; supports SPF; for details see Accessing the AOL Mail System using IMAP & Authenticated SMTP: An Unofficial Guide , Can I use a third-party email program with my AOL email?, and F.A.Q UNIVERSAL E-MAIL AND NEWSGROUPS WHATEVER THE ISP YOU USE (AOL INCLUDED); Warning: AOL expires old messages off of their IMAP server and the AOL IMAP server does not support the IMAP SEARCH command. Also see the aim.com listing above and my AOL/AIM-related bookmarks at del.icio.us / Deflexion.com / HostingProviders / AOL.
17. alterhosting.com -- Courier IMAP, Majordomo mailing lists
18. assortedinternet.com -- cPanel, SquirrelMail, SpamAssassin, Unix shell access, MailMan mailing lists, also see their IMAP page
19. atjeu.com -- cPanel
20. austindev.com -- cPanel
21. avahost.com -- Courier IMAP, cPanel
22. bgxmail.net -- "The World's First FREE 10GB Email Service," discussion about this provider is banned at EMD
23. bigfoot.com -- IMAP seems to be available on Premium and Ultra plans but I cannot find the name of their IMAP server on their site
24. bigimap.com -- Cyrus IMAP, $10/512 MB/month, $12/1 GB/month, $16/2 GB/month, $20/3 GB/month, plus addressing, backups, & more features
25. bitserve.com
26. blogomania.com -- cPanel, exim MTA, SpamAssassin, SSH access upon request for Basic Plan, “370 clients and growing”
27. bluehome.net -- free/gratis, SquirrelMail, powered by Mac OS X Server, SpamAssassin, ClamAV, Procmail, also see this message at EMD
28. bluehost.com -- cPanel, Does Bluehost support IMAP?
29. burntmail.com -- Courier IMAP, $15/1001 MB/year, no bandwidth limit (might be a reason to Look OUT)
30. britain.net (or pla.net or isleofman.net) -- MailSite IMAP server (mail.britain.net), SMTP AUTH, £9.99/?? MB/year
31. california.com and its national counterpart econetwork.net -- CommuniGate Pro messaging server; server-side filtering; Internet connectivity (dial-in, DSL, etc.); they donate 20% of profits to non profit organizations chosen by clients and provide nonprofits with free web pages and internet service
32. caravanmail.net - 100 MB free
33. CIHost.com Shared Unix Hosting and Shared Windows Hosting (aka unixhost.com) -- sued America Online, discussion about the lawsuit and about CIHost.com are at Slashdot.org in AOL Sued For Over-Zealous Blocking, which includes discussion and links about its sordid history including this link and this quote: “For those thinking that CIHost sounds like some insane overlitigous company that tries to use lawsuits to make its profit... You're right. :)”; the Witty Worm took down some of the CI Host servers in March 2004
34. clearlight.com
35. colondot.net -- Exim MTA, SAUCE filtering, FreeBSD system
36. contrasthost.com -- cPanel
37. cornerhost.com -- $50/500 MB/year (basic), $100/1000 MB/year (script), $200/2500 MB/year (shell), IMAP over SSL, SMTP AUTH over SSL, SquirrelMail, ssh for shell accounts, Procmail, Red Hat Linux, FAQ/mail wiki page, off-site status blog, innercircle mailing list; many users, including BenHammersley.com
38. crnc.net -- H-Sphere or cPanel control panel, forum, used by del.icio.us, (before you sign up, ask crnc.net if the plan you are interested in includes IMAP)
39. crontime.com
40. crystaltech.com -- servers run an MS operating system; IMail 7.13; CRAM-MD5 authentication; virus scanning; backups & restores; webmail; 250 MB mail storage in addition to web storage; ASP/.NET; discussion forums; no ssh???; happy customers
41. ctyme.com (aka marxmail.net) -- Exim MTA, SpamAssassin, SquirrelMail, subaddressing, used by Lawrence Lessig as discussed in this 2004-Dec-14 blog item; planning to switch to Dovecot IMAP; also see this thread at EMD; Warning: As posted here, Mark Perkel, the ctyme.com CEO, is "someone who works from home and . . . I would not want to be prohibited from running an email server from home."
42. cwazy.net (aka cwazy.co.uk, zapo.net) -- 350 MB free, Cyrus IMAP, SquirrelMail, forum; also see this 2005-July-30 EMD message by stevew, a cwazy.net representative
43. cyberbite.com -- Verio reseller; as you can see in the viaVerio Signature Hosting entry in the table above, I use and recommend the Verio Signature Hosting account
44. dathorn.com -- cPanel, $13.50/2 GB/month
45. dbtec-networks.de -- Cyrus IMAP, sendmail, SquirrelMail, Solaris OS, Bynari InsightConnector groupware packages available, site is in German
46. deru.net
47. digitaldaze.com
48. digitalspace.net - the fact that they currently support IMAP is mentioned in the FAQ, but note that they say that IMAP “support is not guaranteed at this time for security reasons”; high price/MB/year
49. DeepMail.com -- Anti-Spam & Anti-Virus Protection; CommuniGate Pro IMAP; $9.95/100 MB/month; +$3.95/+50 MB; daily backups; ¿¿¿restores???
50. dombox.com -- site available in English and German, Swiss Company, related to swissmail.org (see below)
51. domehost.com -- cPanel
52. doorhost.net -- cPanel, Forums, including an Email Forum
53. dr2.net -- cPanel; according to this thread, it is run by a 16 year old
54. eapps.com
55. easynetdial.co.uk -- Brightmail spam filtering
56. econonethosting.com -- forums
57. electric.net --
58. electricmail.com -- Sophos AV
59. enhancedhost.com -- Plesk 6, SquirrelMail
60. enic.cc -- domain name registrar
61. eskimo.com -- UW IMAP, alt SMTP port (2525), LB4S (‡), SquirrelMail, shell access, MindTerm web-based SSH client, Usenet, local NNTP groups (announcements & lobby), discounts for Linux User Group members, discounts & extra storage space for pre-payments, virtual domain discounts if you link to eskimo.com on your web site. Also see Jessamyn West's why eskimo.com? I have recommended Eskimo.com as an Internet access provider and my friends & family who use them are quite happy with their non-corporate friendly service. [Note that until Summer 2004, Eskimo.com used a very old IMAP2bis server.]
62. eumx.net (aka mzplanet.com) -- RoundCube webmail, Support Forum, “We will disable POP3/IMAP access between June 9 and 13 [2005] due to testing and service optimisation.”
63. evenmail.com -- “established in February 2004”; (lots of English language and grammar mistakes on this site)
64. everyhost.com -- related to everybody.org
65. everyone.net -- personal and group accounts; FAQs, including IMAP FAQs; no shared mailboxes
66. ez-web-hosting.com -- cPanel, SpamAssassin, double redundant nightly backup
67. ezrs.com -- SquirrelMail
68. f15.com -- $19.95/1000 MB/year
69. fatcow.com -- in business since 1998
70. fazter.com -- also see this pop-up window and Is This Copyright Infringement? International Email Hosting Company Asks You to be the Judge
71. featureprice.com -- went out of business 21 May 2003 and seems to have been reborn in mid August 2003 with IMAP support; (Here is what I said about the pre 21-May-2003 incarnation of FeaturePrice: the fact that they do not support IMAP is in the Sales FAQ; also see the review of FeaturePrice.com at 10-best-web-site-and-domain-hosting-services.com)
72. fidelityhosting.com
73. finalasp.com -- MS Exchange server, Outlook Web Access, Knowledgebase, $19.95/150 MB/month
74. flashmail.com -- seems to be using NetWin Server Software
75. flexihostings.net -- cPanel, forums
76. focalhosting.com -- they don't say how much space you get!?
77. forest.net -- Postini spam and virus filtering, CommuniGate mail server
78. freedom2surf.net -- Cyrus IMAP (inmail.f2s.com), virus protection updated daily
79. freemail.com.cy
80. freemail.nx.cninfo.net -- 5 MB free, site is in Chinese Simplified
81. frontdrive.com
82. fusemail.com -- personal and group accounts, Courier IMAP, SpamAssassin, ClamAV, customized SquirrelMail, RSS feeds, lots of plans including $19.96/350 MB/year and $71.88/1250 MB/year; no bandwidth limits (might be a reason to Look OUT); “Block 100% of Spam and Viruses” (might be another reason to Look OUT); shared mailboxes, address books, calendars for group accounts; FuseMail Forums including a Checking Mail with IMAP forum; Bug database; address-book greenlisting; no headers that state original envelope addresses (discussed below); server-side saved search folders; no support for IMAP keywords, address book does not support distribution lists; “I [Site Admin] am not certain that the server-side sorting functions can be utilized here at FuseMail at this time [2005 April 15]”; referral program; also see Fused Personal Basic Plan vs. Fused Personal Free Plan in the FuseMail forum, the EMD thread Yahoo terminated 2 of my accounts - is it because of FuseMail??, and this, this, and this EMD thread; Question: Do they do backups & restores???
83. FutureQuest.net -- Courier IMAP, qmail MTA, no access to .qmail files, SpamAssassin, forums, also see the User Reviews and Ratings of FutureQuest at WebHostingRatings.com
84. geekisp.com -- Courier IMAP over SSL, SquirrelMail, Qmail MTA, TMDA, TMDA-ofmipd, SpamAssassin, OpenBSD, domain hosting
85. gnu-darwin.org -- SquirrelMail; if you donate $15 or are a GNU-Darwin contributor, you get 1 year access to a full featured email account with a user@gnu-darwin.org email address; supports SSL; GNU-Darwin shell access; free 1-month trial subscription
86. gradwell.com -- Courier IMAP, virus scanning, SpamAssassin for an extra fee, SMTP AUTH, +£10.00 (plus VAT)/+100 MB/year, text (non-binary) Usenet access
87. gravital.net -- Courier IMAP, TMDA C/R filtering, FreeBSD
88. gsp.com -- LB4S, also see Virtual Server E-Mail, (they seem to be Verio resellers, which is a good thing IMHO)
89. homepageuniverse.com -- Plesk control panel, Horde/IMP, SquirrelMail, forums, including a DomainMail forum, “looking into the possibility of offering MS Exchange”
90. hostcolor.com -- UW IMAP
91. hostdepartment.com -- daily backups, a restore is $25, Horde/IMP, HostDepartment.com supports The Horde Project
92. hostdesigns.com -- Icewarp Merak Mail Server
93. hostforweb.com -- cPanel, they state “Procmail support” but someone emailed me and told me that HostForWeb.com no longer lets users use Procmail, support forums
94. hostgator.com -- cPanel
95. hostgo.com
96. hostica.com -- SquirrelMail, IlohaMail, SqWebMail, Horde/IMP, also see Email Support
97. hosting365.ie -- also see I love my webhost, you should too
98. hostingmatters.com (aka hostmatters.com) -- UW IMAP, Horde/IMP, Neomail, Squirrelmail, SpamAssassin, cPanel, Fantastico; "Shell access is available on request for supported packages"; Backups; Offsite emergency status page; Email Forum; as discussed in this thread, their IMAP server is slow; as blogged here and here, recommend by Shelley Powers of Burningbird.net; as blogged here, used by Teal Sunglasses
99. hostingworks.com -- Courier IMAP, 30-minute login before SMTP (‡)
100. hostit365.com
101. hostpacket.net -- SpamAssassin
102. hotbox.ru (aka mail333.com) in Russian or English -- 20 MB free
103. hp.com -- Premium account supports IMAP, $11.95/100 MB/month, MS Exchange Server
104. hub.org -- $99.99/256 MB/year, Cyrus IMAP, Horde/IMP, Sieve, spam tagging, virus filtering, FreeBSD shell access, pine, unlimited domain hosting included
105. hummingbirdhosting.com -- domain registrar, the Setting up a User (email account) using the Ensim Control Panel mentions IMAP
106. hushmail.com -- PGP compatible secure email; IMAP access available in Premium and Business plans; also see IMAP Access in the Hushmail Help system; started by Phil Zimmermann, the creator of PGP
107. i12.com
108. i8k.com
109. icdsoft.com -- IMAP over SSL, Courier IMAP, SpamAssassin, login before SMTP (‡)
110. icmail.net -- 1000 MB free
111. ideanode.com -- SquirrelMail, Plan Details (for geeks) says “High-Performance IMAP server” (which is not geeky enough for me and makes me wonder what they are hiding; might be a reason to Look OUT)
112. iinet.com
113. iMagineis.com -- Red Hat Linux; UW IMAP
114. imap4all.com -- Bronze/Silver/Gold comparison table, extra space is +€1/250 MB/month, IMAP over SSL, SMTP AUTH, backups, restores cost €100, Horde/IMP, 15-day trial, Dutch company; also see this 2004-July-16 EMD message from the IMAP4all Administrators
115. impacthosting.com -- MailSite IMAP, virus scanning
116. indoglobal.com -- Courier IMAP, SMTP AUTH, virus protection, optional SpamAssassin and/or C/R filtering, ssh access, WebDAV, Indonesian company (I think), U.S.-based servers
117. infinology.com Virtual Private Server plans -- webmail, sendmail MTA, I don't think their low-level accounts support IMAP, but this makes me think their high-level accounts do
118. inmail24.com
119. innerhost.com -- UW IMAP, sendmail, .Net
120. internetconnection.net -- Courier IMAP
121. inwa.net -- Courier IMAP, qmail MTA, Horde/IMP webmail, located in Washington state
122. io.com (formerly "Illuminati Online") -- Internet connectivity, five levels of spam filtering protection (including SA), SquirrelMail, Mailman mailing list hosting, cool Staff page
123. izymail.com -- 15-day free trial, $6.05 one-time signup fee + $13.25/6 months, can access AOL, MSN, Hotmail, & Yahoo mail
124. jager.com -- free; 3 MB storage space
125. jiffynet.net -- FAQs, the table says “IMAP Mail - Horde Mail”, but they seem to be more focused on “POP Accounts”
126. KangaWeb.com -- the fact that they support IMAP is in the Email FAQ; weekly backups, SpamBoxer
127. ktb.net -- Dovecot IMAP, shell access, procmail
128. laughingsquid.net -- Courier IMAP, Horde/IMP Webmail, IMAP over SSL, Email FAQ; as discussed here, laughingsquid.net is by boing boing pal Scott Beale
129. likk.net -- free (gratis), Zope hosting (?), 100% Microsoft free
130. location7.com -- $35 (£20+VAT in the UK) / year / 100 MB, Courier IMAP, FAQ, Virus and Spam Filtering, Mail Provider Comparison Chart
131. loftmail.com -- $35.40/1000 MB/year (Corporate), free/gratis accounts do not support IMAP, Cyrus IMAP over SSL, Horde/IMP, server-based filtering via Sieve, ManageSIEVE protocol, no headers that record original envelope addresses, backups for all, free/gratis restores for Corporate accounts, OpenBSD, optional greylisting, maximum email size is 200 (!) MB for Corporate accounts
132. lunarpages.com -- Horde/IMP, cPanel, Fantastico Script Library, “SSH is disabled on all servers except the dedicated hosting plan and enterprise plan which has limited SSH support.”; lots of forums including a forum about email
133. lycos.co.uk -- free and pay accounts include “HTTP/IMAP” (I do not know if this means you can use any IMAP client to access your Lycos.co.uk mail -- does anyone know???)
134. macosx.com (aka macsrule.com) -- virus scanning; SpamAssassin upon request; Courier IMAP; SMTP AUTH, SquirrelMail, Horde/IMP, Email FAQ, $9.95/yr for 5 MB; 1.99 sort key^†
135. macrefuge.com -- according to their FAQ, they offer IMAP but not WebDAV (so it's not truly a replacement for DOTmac)
136. macteens.net -- 1 gig free, SpamAssassin, ClamAV, support forums
137. magicaldesk.com -- SyncML, also see this thread at EmailDiscussions.com
138. mail.az in Azerbaijani, Russian, and English -- 10 MB free
139. mail15.com / mail333.com -- 15 MB free, IMAP over SSL, SMTP over SSL, ad free, no tag lines
140. mail2web.com -- $1.99/200 MB/month, based on Microsoft Exchange
141. mailandfiles.com -- Courier IMAP, no outgoing SMTP, $5/50 MB/month
142. mailfetch.net -- unlimited bandwidth (might be a reason to Look OUT); seems to be a FuseMail reseller (another reason to Look OUT)
143. mailstates.com - this site crashed Opera so I'm wary of them; requires Java
144. mcm.net -- 4 MB free, in French
145. mediatemple.net -- Email KnowledgeBase, weblog; as discussed here, used by TheManInBlue.com
146. memset.com -- cPanel
147. mi8.com -- Microsoft Exchange Hosting & Outsourcing, includes MAPI, POP/IMAP, and OWA (Outlook Web Access)
148. microneil.com -- $2/mailbox/month + $0.25/MB/month, virus and spam filtering
149. mintchaos.com
150. modwest.com -- Cyrus IMAP, ssh access, nice Knowledge Base system with user comments
151. .mp (ccTLD of Northern Mariana Islands) -- 1 Gig combined IMAP/web storage; Personal-Site (PS) FAQ; Commercial-Site (CS) FAQ; PS Terms of Use; also see the thread Dot MP Up and Running at RussellBeattie.com; make sure you read their Terms and other legal documents before you pay
152. mstrata.com -- Courier IMAP, non-optional spam and virus protection, $20 Setup Fee + $10/100 MB/month, you need your own domain name
153. myacen.com virtual (enterprise level) and reseller hosting -- SpamAssassin installed; this discussion thread on their forum makes me think they don't grok IMAP
154. myecom.net -- 10 MB free
155. myownemail.info -- 2 MB free
156. mythic-beasts.com -- IMAP over SSL, Exim MTA, procmail, SMTP AUTH,
157. mywebwizards.net -- SSH access
158. N1hosting.com -- list of installed software versions, including IMAP software, is here
159. nasstar.com -- UK company
160. neathosting.net -- cPanel, recommended by Natalie Downe
161. neomailbox.com -- see also Service features and specifications; personal subdomain, IMAP over SSL, SMTP over SSL, Razor spam detection, ClamAV virus detection, Open BSD, $39.95/150 MB/year, bandwidth limited to 200 MB/month, extra bandwidth for a fee
162. netservers.co.uk -- virus filtering
163. networld.com -- CommuniGate Pro
164. Networth Enterprises -- SpamAssassin; NetWorth Enterprises donates to evolt.org 10% of hosting and reseller services revenues paid by evolt.org members (“evolt.org is a world community for web developers, promoting the mutual free exchange of ideas, skills and experiences”)
165. neucomm.com -- dial-in access in US and Canada; Courier IMAP
166. neureal.com
167. newatech.com -- “space used by your mail accounts... is unmetered”; company located in Seattle and Nepal
168. nexpoint.net
169. nightskyhosting.com -- qmail, TMDA
170. ninthwonder.com
171. no-more-spam.de -- in German, TMDA (Tagged Message Delivery Agent ) C/R filtering
172. nwnexus.com
173. nyi.net -- also see their packages; According to Netcraft.com, nyi.net was the #1 Most reliable and fastest hosting company site during June 2003
174. oeone.net -- WebDAV, free 60 day trial
175. Omnis Network
176. opensourcehost.com -- cPanel, SpamAssassin, Drupal hosting, special offer if you set your Referral ID to drupal; another special offer if you type CMS as the referrer
177. ot.com -- $15/100MB/month, 5 login IDs, unlimited addresses @yourdomain
178. perso.be -- according to this message at EMD, they use IMP based Alinto outsourcing and you get 10 MB
179. personalsites.org -- cPanel
180. phatcom.net -- Courier IMAP, 100 (or 50?) MB free, SquirrelMail, SpamAssassin, no outgoing SMTP
181. ploghost.com -- cPanel, no ssh or telnet access, company in Philippines, servers in Europe and U.S. (I think)
182. pobox.com (aka rightbox.com and onepost.net) -- "Mailstore" (which includes IMAP) account is $50/100 MB/year; Postfix, reject addresses and more
183. promptpost.com (or veloxmail.com; squeml.com; mc2post.com; ezeml.com; icaremail.com; swifteml.com; wingedmail.com; epo.st; email1.st) -- 130 MB free, donations accepted, Courier IMAP, SquirrelMail, discussion groups, can host at most 100-150 active users, one-man operation (the last two are reasons to beware IMHO)
184. pubbox.net (aka pubbox.de) -- 100-1000 MB free/gratis, Courier IMAP, SqWebMail and CAMAS webmail, Bayesian spam filters, Exim MTA, DragonFly BSD operating system, servers located in Berlin, Germany; one-man operation; also see the EMD thread titled pubbox.net - Interesting Free IMAP/SMTP service
185. python-hosting.com
186. rcthost.com -- cPanel
187. redmail.com -- +£99.95/ +1 GB / year
188. redpin.com -- Courier IMAP, qmail, exim, SpamAssassin, no virus filters
189. remarkablehosting.com -- SMTP AUTH, FAQ
190. revisemedia.com -- Wordpress hosting
191. rt19.com -- UW IMAP
192. rhyton.com -- ssh access, +$1/+1 MB/month
193. sandershosting.com
194. sentinare.com -- according to this page, they use Maia Mailguard
195. serverintellect.com -- SmarterMail webmail, Microsoft servers
196. sh3lls.net
197. shiremail.com -- £3.50/10 MB/month
198. shore.net (primus) -- SMTP over SSL/TLS, exim, Using Pine to get Mail, Comparing POP and IMAP
199. shutmail.com -- 3000 MB free, also see this thread at EMD
200. sify.com -- 15 MB, DomainKeys support, located in India
201. simplicato.com -- Courier IMAP, Web Mail, ClamAV, SpamAssassin, FAQ, IMAP vs. POP3 by Brett B Shere (this article needs to be edited but it shows that they are IMAP fans)
202. site5.com -- cPanel, not much info about IMAP although it is listed in their comparison table, mbox-formatted mailboxes, Horde/IMP, NeoMail, SquirrelMail, LB4S (‡), Knowledge Base, Forums, Fantastico, Ruby on Rails, affiliate program, “IMAP folders are allowed, it's the IMAP subfolders that aren't allowed.” (might be a reason to Look OUT), also see site5.com weblog
203. sitelutions.com -- SpamAssassin, mail-only accounts available, Package Comparison Matrix, no ssh access on shared hosting accounts
204. slashmail.org -- “for individual use only,” UW IMAP over SSL, Sendmail, SquirrelMail, DSPAM, Clam AV, & more, alt SMTP port (225), traditional Unix mbox format mailboxes, “No E-mail Storage Limits!” (might be a reason to Look OUT); affiliated with ucebee.com
205. smileglobal.com -- “20 Email Boxes, 100 MB Storage Per Box, 2 Gig of Total Storage”
206. snailmail.ch -- free, mail.snailmail.ch is using Courier IMAP
207. softflare.com -- qmail
208. speakeasy.net -- Courier IMAP, SMTP AUTH, server-side spam/virus filtering, Usenet news server, also see I hate Mandatory Mail Filtering!!!! - speakeasy.net bites the dust. (was "I hate SpamAsssassin") in gmane.mail.spam.spamassassin.general
209. spry.com
210. stgeorges.myvnc.com -- 60 MB free, Merak Groupware to sync Contacts/Task List/Calendar/Notes with Microsoft ® Outlook; also see the thread "Just signed up at stgeorges.myvnc.com" at EMD
211. sudio.com -- Plesk control panel, Horde/IMP, also see POP & IMAP Email Account (Mailbox) in the KB, Sudio Inc. contributed a nice skin to the Horde/IMP project
212. superbhosting.net
213. superb.net -- used by Gary Lawrence Murphy
214. surpasshosting.com -- cPanel; Fantastico; Email discussion group (requires log in); as discussed in this blog entry, used by cookingforengineers.com
215. terabolic.com -- Cyrus IMAP, $39.95 / 50 MB / year
216. teramail.com -- SquirrelMail, Postfix, site is in Korean
217. texas.net
218. textdrive.com (aka joyent.com) -- Postfix MTA with plus addressing, Dovecot Courier IMAP, IMAP over SSL, SMTP over SSL, WebMail (IlohaMail, SquirrelMail, Horde/IMP), SpamAssassin, Webmin control panel, no subaddressing, WebDAV, iCal, FreeBSD, discussion forum, affiliated with Textpattern CMS, supports Textpattern, WordPress, Instiki, Ruby On Rails, and more, $12/300 MB/month, $25/1000 MB/month, or $40/2000 MB/month, shell access, SFTP access (but no FTP access), Procmail, Mutt, no Pine (which might mean they are not especially supportive of IMAP users); Status blog at status.textdrive.com; backups & restores; “50% of [TextDrive] proceeds go to Rails development”; used by Evan Williams and Keith Devens; Privacy Policy, Safe Harbor Policy; Planning on VPS plans someday; also see the thread Getting very nervous about production reliability / availability in the TextDrive forum, the blog item Bad customer service at rc3.org, and the thread Lingering e-mail problems? (which is about a painful upgrade to an alpha version of Dovecot IMAP). Also see my TextDrive-related bookmarks at del.icio.us / Deflexion.com / HostingProviders / TextDrive.
219. thebestisp.com -- $29.95/300 MB/month
220. thehostingcompany.us
221. thoughtlocker.net -- ssh access
222. tigahost.com -- sendmail, located in Hong Kong
223. tilted.com -- located in Forest Park, IL, USA
224. tiscali.com -- 10 MB free; Internet connectivity (dial-up, broadband) in many countries, for example in the UK via tiscali.co.uk
225. totalchoicehosting.com (aka TCH) -- cPanel, Horde/IMP, SquirrelMail, NeoMail, exim MTA, no SSH (as of 2003 May 16), Jail Shell, also see Procmail/spamassassin Weirdness in the TCH forums
226. uk2net.com -- Gold account supports IMAP; for warnings, see this thread at EmailDiscussions.com
227. ukshells.co.uk -- Courier IMAP, transitioning from RedHat to Slackware Linux, SpamAssassin, procmail, SSH access for “shell account” plans, also see forums
228. ultradesign.com -- 20 MB per mailbox (makes me wonder if they grok IMAP); Mac OS X servers; Remote Administration, Webmail, Autoresponders, Anti-Virus and Anti-Spam; owner affiliated with Spamhaus.org
229. unitedemailsystems.com -- 3 GB free, forum, also see this 2005-July-30 thread at EMD
230. valai.net
231. valueweb.net -- Sending/Receiving Email mentions IMAP; Brightmail spam filtering; PC Magazine Editors' Choice (25 March 2003)
232. venturesonline.com
233. vervehosting.com -- Horde, Neomail, spam & virus filtering (including SA), cPanel
234. virtualnames.co.uk -- spam filtering, 30-minute LB4S (‡)
235. viperhost.com -- cPanel
236. visi.com -- Courier IMAP over SSL, Internet connectivity, Authenticated SMTP over SSL, Procmail, Postini, SpamAssassin, procmail, ~35,000 Usenet newsgroups, nn newsreader
237. visitmail.com -- in French, UW IMAP
238. vnmails.com -- mail.vnmails.com seems to be a Merak IMAP server, 10 MB free
239. vonetwork.net -- cPanel
240. voxel.net
241. webhost4life.com -- .NET
242. webintellects.com -- as discussed here, the patch command is not available
243. webmail.us (aka excedent.com) -- $30/1024 MB/year, business and user plans, 99.99% uptime guarantee (but make sure you read the SLA section of the TOS), Dovecot IMAP, Postfix MTA, ClamAV, SpamAssassin, customized SquirrelMail, Red Hat Linux, “Certain administration features of this site require Microsoft Internet Explorer 5.0 or higher and will not function with most versions of Netscape.”; “There is a $100 fee per mailbox for data restores.”; “Is there any chance of webmail.us implementing greylisting? ... probably not anytime soon.” (might be a reason to Look OUT); also see the blog of Webmail.us CEO, Pat Matthews, The Webmail Blog, the blog of Bill Boebel, the CTO of Webmail.us, and the blog of Mike Bulman, a Webmail.us team lead; As of May 2005, ~5500 customers, excellent customer service
244. webservehosting.com - cPanel and Fantastico
245. wikidev.net -- 12.93€/3000 MB/month; Cyrus IMAP, Horde/IMP webmail, Debian/Gnu Linux, MediaWiki hosting; ~27 customers (including me :-)); run by MediaWiki developer Gabriel Wicke, who you can learn about here, here and here
246. xensia.net -- Courier IMAP, IMAP over TLS/SSL, SMTP AUTH, Webmail, Control Panel, user-configurable SpamAssassin, servers & corporation located in UK
247. xlinternet.com -- Ensim, SquirrelMail, Majordomo, used by Wikitravel.org
248. xmission.com -- Internet connectivity, SpamAssassin, Horde/IMP Webmail, xmission.* newsgroups, 7 MB email quota (I think this quota is only for the primary INBOX and not for other mailboxes in your IMAP mailstore)
249. zettai.net -- SpamAssassin, virus protection, SquirrelMail, Courier IMAP, Zope hosting, WebDAV, Email FAQ, How to Use the E-mail System, Backups FAQ, no Procmail, no Sieve, Forums
250. zipmail.com -- $11.99/50 MB/year
251. zzz.com -- Internet connectivity

For Power Needs: Outsourcing, Co-Location, and Dedicated-Server Options

If you need lots (gigs) of space or you need to provide IMAP services to lots of users, see

• aktiom.net
• bytemark-hosting.co.uk -- as discussed here, Mark Pilgrim uses Bytemark; referral program; if you decide to sign up, use this link and Bytemark will make a donation to the Debian Project
• ispserver.com
• JohnCompanies.com -- FreeBSD or Linux; 0.20 sort key (0.12 sort key for Open Source Software contributors); +$2.00/+2 GB/month; 10% discount for annual payment; JC does backups & restores for no extra fee, but you need to tell them which directories to back up; also see the JC ad and comments at Kuro5hin.org; if you sign up with John Companies and want to help Infinite Ink, please put col00929 (my JC customer ID) in the referral field
• rimuhosting.com -- VPS and Dedicated Linux servers, wiki-blog
• RoseHosting.com -- 0.18 sort key
• Tucows.com has an email reseller plan
• Verio.com has a number of VPS (virtual private server) plans -- I use VPS2, which uses FreeBSD and no NFS (yay!); Verio is expensive but, based on my experience, they are very good; if you sign up with Verio, please let me know so I can "take the credit"!
• Q: comparison shop for dedicated web hosting at Google Answers -- this includes recommendations for providers and discussion about how to find a provider
• User-Mode Linux Hosting Providers listed here and here -- “User-Mode Linux (UML) lets people run a virtual Linux system totally separate from other users of the same machine.”
• Russell Beattie Notebook: What to do about EV1? (2004 March 3) -- the comments include an interesting discussion about various providers
• Ask.MetaFilter.com: What's a good heavy duty webhost? (2005 Nov 07)
•  I am collecting co-location- and dedicated-server-related links at del.icio.us/Deflexion.com/HostingProviders/Colocation and HostingProviders/*

Also some of the providers in The Table above have outsourcing or reseller plans. For example, luxsci.com has a “Private Labeled WebMail” option.

Look Promising, But Do They Do IMAP?

• acmemail.net -- free, IMP webmail client
• addr.com
• BlueDomino.com -- no telnet/ssh access; also see this DreamHost vs. BlueDomino thread
• ChooseYourMail.com
• downtownhost.com
• flashmail.com -- free, CWmail webmail client
• ft.com PersonalOffice
• H2Hosting.com / 59Hosting.com -- SpamAssassin; SSH access upon request; remote backup; their Netcraft uptime stats; very responsive customer support
• Hostingplus.com -- RedHat Linux variation
• ipowerweb.com -- see the User Reviews and Ratings of iPowerWeb at WebHostingRatings.com; I have received many spam messages promoting this company -- at addresses that I never give out -- so I recommend boycotting them; I've also seen a lot of articles/postings warning people to avoid iPowerWeb.com
• InternetConnection.net
• katamail.kataweb.it -- free, in Italian
• MyLinuxISP.com -- Postini filtering
• prohosting.com -- no shell access???
• rightonthemark.com -- 3 MB free, CommuniGate Pro mail server, server-side filters
• seznam.cz -- 10 MB free
• unacom.net -- the only occurrence of the word “IMAP” on their site is in the “old” directory on this page
• weblogger.com -- PLESK control panel, Manila hosting

Problematic Providers

Many of the providers in this section do not focus on IMAP, but instead focus on other services such as web hosting, spam fighting, or Internet connectivity. This means that the IMAP criteria that I am using to evaluate them are not what their business is focused on. I include them here . . .

• so that I can easily check in on them and see if they've changed their fees or services
• so that I know that I've already checked them out
• because they might be of interest to people reading this page

IMAP Service Providers with a High “Price per Meg per Year”

These providers let their users use IMAP to access their mailboxes, but they are, in my opinion, charging too much for the amount of IMAP-accessible space they provide. Space is cheap these days and if a service provider understands IMAP, they understand the need for lots of space. It's fine to have bandwidth limits and charges, but storage space should be cheap cheap cheap!

• 123mail.net -- extra charge for virus scanning; Courier IMAP
• catalog.com
• drizzle.com -- option to enable SpamAssassin
• DucTape.Net
• frii.com
• inwa.net -- UW IMAP, Horde/IMP, “Our intellegent [sic] e-mail pre-processor, checks for anything that smells like spam and files it away for further analysis.”
• Loadmail.com
• netenergy.net -- £19.95/10 MB/year
• NetHK.net
• rahul.net (a2i Communications) -- various types of mail filtering available
• solarhost.com -- imail.solarhost.com seems to be an IMAP server; “powered only by 100% renewable energy”
• swissmail.org -- site available in English and German
• syclone.net
• thelix.net -- IMAP available on Advanced, Premium, and Ultra accounts (but not Standard accounts), Courier IMAP, 90 minute LB4S (‡), optional C/R filtering
• webhosts.co.uk
• zxmail.com -- right column contains IMAP packages

Probably No IMAP4rev1

As far as I can tell, the following providers do not currently support IMAP4rev1, which is the current version of IMAP.

• aitcom.net -- As discussed in this Google Answers thread, there are many people who are unhappy with AITcom.net
• AletiaHosting.com -- there's no mention of IMAP in their Manual or FAQ
• aplus.net -- also see their Web Mail Plans & Prices and the comp.mail.misc message Abuse of Unsuspecting Webmail Users and the User Reviews and Ratings of Aplus.net at WebHostingRatings.com; IMAP is mentioned on their site here but according to this message, they do not support IMAP
• aventuremail.co.uk (aka aventuremail.com) -- $4.99/5 GB/life service, RoundCube webmail
• cotse.net
• emailfiltering.co.uk -- spam & virus detection of email that's sent to your pre-existing POP account(s); £1.75/month (one-month free trial); uses MS ActiveX technology & prefers MSIE 4.0 or higher; currently does not support IMAP
• Earthlink -- port 25 hijacking; no IMAP; Brightmail filtering (called Spaminator); challenge/response filtering. For more about their challenge/response filters, see EarthLink to Offer Anti-Spam E-Mail System by Jonathan Krim at The Washington Post (2003 May 7) and How EarthLink Is Blocking Spam For 5 Million Users By Mitch Wagner at InternetWeek.com (2003 June 6). According to this 2004-Jan-7 CNN article, they have “roughly 5 million paying subscribers.” As of April 2004, option to use @PlaneteBay.net email addresses. Supports DomainKeys.
• Gmail.com -- “A Google approach to email” that is currently available by invitation or by submitting a U.S. mobile phone number; ∞ + 1 Gig free; AJAX-based webmail; POP over SSL; SMTP AUTH over TLS; virus filtering (probably based on Sophos); if you use the Gmail outgoing SMTP server, you must use one of your authenticated Gmail addresses in your From: header line; uses DomainKeys Identified Mail (DKIM); subaddressing (discussed below); each incoming & outgoing mail msg must be 10 MB or less; account closed if 9 months of no activity; Also see my Gmail-related bookmarks at Del.icio.us/Deflexion.com/HostingProviders/Gmail, Gmail/Tools, and Gmail/Discussion
• gmx.net (aka gmx.de, gmx.ch, etc., affiliated with 1und1.de) -- one of the largest providers of free email in Germany; to use their premium service, you must have a German bank account; if you use the gmx outgoing SMTP server, you must put your gmx address in the From: header of your outgoing messages; In this 11-Jan-2004 message, Mark Crispin, the inventor of IMAP, said “gmx.de is well-known not to run a real IMAP server”; also see this 2002-Dec-04 message from Sam Varshavchik in which he said “Anything [such as the gmx server] that cannot receive mail addressed to multiple recipients cannot be technically described as a "mail server".”; also see the 2004-08-12 thread GMX increases free storage to 1GB at EMD.
• godaddy.com Email Accounts -- WebMail, spam filters; email services are also available on their webhosting plans; also see their Email Tutorials; note that godaddy.com is mainly known as a domain name registrar (and there are many people who are happy with their services); according to this message, they “do not provide IMAP support for our email services.”
• he.net -- users can track and seed files via BitTorrent
• herwebhost.com -- there's no mention of IMAP on their site
• hostbaby.com
• hostway.com -- introduced CleanMail spam and virus detection on 20-Jan-2004; as discussed in their Email FAQ, “Hostway does not support IMAP.”
• hotmail.com (aka "MSN Hotmail") -- HTTPmail (MS's proprietary alternative to IMAP) for pay accounts (but not for new free accounts); .NET Passport required; Brightmail spam filtering; 250 MB free; "MSN Hotmail Plus" package is $19.95/2000 MB/year; webmail requires cookies; between 60 and 180 million accounts (?); also see MSN Hotmail Fun Facts
• inbox.net -- as discussed in this Q&A, they currently do not even support POP, forums
• interland.net -- the only mention of IMAP on their site is in the KB article Mail Users Receive Duplicate Copies of E-mail, and this is in a generic comment that is not specific to Interland
• ixwebhosting.com
• netbasiks.com
• Netscape Mail -- 250 MB free; virus protection; mail is accessed via the NIM module, which is a proprietary Netscape enhancement; also see the Mozilla FAQ; Starting 2006-Aug 19, Netscape Mail will support IMAP
• no-ip.com -- spam and virus detection
• operamail.com -- free/gratis and premium accounts, hosted by Outblaze Ltd.
• phpwebhosting.com -- their FAQ says that they do not support IMAP
• sonic.net -- SpamAssassin and Graymail, Spam FAQ, Graymail FAQ, procmail, Squirrelmail, Mail Snapshots and Retrieving files from snapshots
• spymac.com -- 1 gig free (as of 2004 April 5); SMTP AUTH as of 2004 Sept 24; “IMAP mail capabilities are under development”; webmail clent based on @Mail; WebDAV; discussion forums; also see this, this, and this thread at EMD
• webmasters.com -- the fact that they don't support IMAP is in their knowledge base (search for IMAP)
• webstrikesolutions.com
• Well.com (The WELL) -- SpamAssassin; basic virus scanning, procmail; also see Filtering with Pine at well.com; more about SpamAssassin -- & The WELL in general -- is in Dealing With Spam using SpamAssassin at The WELL and in Andrew Leonard's Spam vs. spam at Salon.com
• workspot.com -- $9.95/month, 100 MB, WebDAV, you can use a full graphical Linux “desktop and software through a web browser, from anywhere in the world”  (they are planning to implement IMAP)
• Yahoo! Mail Plus and Yahoo! Mail POP Access & Forwarding -- webmail requires cookies, subaddressing (discussed below), disposable email addresses for Yahoo! Mail Plus users, qmail MTA with this bug, Rocketmail technology, Network Appliance (NetApp) network file server, $19.95/2 GB/year, DomainKeys support;  Also see my Yahoo-related bookmarks at del.icio.us / Deflexion.com / HostingProviders / Yahoo
• zoemail.com -- disposable addresses; “patented AT&T Labs anti-spam solution” (might be a reason to Look OUT); “ZoEmail is a web-based e-mail service ... POP3/IMAP compatibility will be available in future ZoEmail upgrades.”
• zworg.com (irk.ca) -- webmail and POP, custom software

Out of Business or Acquired

The following providers used to be listed above. I include them here because they might provide clues about types of providers to avoid.

• axentra.net -- 25 MB free, SquirrelMail, LDAP-accessible address book, iCal; As announced in this 2005 Sep 9 message, “the axentra.net service will be retired ... on October 9, 2005.”
• Bloghosts.com -- cPanel, user discussion forum, SSH access upon request, +$2/+50 MB/month, “built and run by bloggers”; no new customers after 2004-Nov-09; servers will be shut down 2005-Jan-01; details here and here 
• emailaccount.com -- owned by Edwin Hayward who also owns EmailDiscussions.com (EMD); “Mail Plus” and “Mail Plus Total Protection” accounts include IMAP; >130,000 users; currently using Everyone.net but “We've made an arrangement with a leading email service provider to buy our service.”;  As announced 8-Jan-2004, they were bought by MailBlocks.com (which is discussed in table above)
• galaway.com -- free/gratis, Courier IMAP, the top page says “We prosecute each and every spam attempt!” but anyone who knows anything about administering an email system knows that this is impossible (my conclusion: they may be clueless); As discussed here, Galaway.com was acquired by Runbox.com in June 2005.
• Info Aggregator (IA) -- RSS-to-IMAP service; details about IA's closure are in this blog item
• pumapost.com (or many other domains) -- Courier IMAP, SquirrelMail, SpamAssassin, ClamAV, affiliated with promptpost.com; as discussed in this thread at EMD, PumaPost.com will “shut down on 24th December 2005.”
• sytrino.net -- 3 gig free; as posted in this 2005-Jan-12 message by Edwin, discussion about this provider is banned at EMD; also see this 2005-Jan-23 blog entry titled Watching children at play, which says the following about Sytrino.net: “This guy is advertising a service which he has no hope of actually deliverying upon, so innocent victims are going to be left high and dry when this "free email service" disappears because the ISP shuts him down for ToS violations.”
• thinbrowser.com -- 1000 MB free; according to this 2005-April-07 EMD message, thinbrowser.com was acquired by bgxmail.net in April 2005
• zapmail.net -- for details see the 2006-Jan-01 EMD thread about zapmail.com ramping down

Other providers that have gone out of business or have stopped accepting new customers are listed in The Table with a gray background.

Providers Offering Message Deflexion (including deflexion to or from IMAP servers)

Sometimes it is useful to have messages available in a data format or through a protocol that is different from the original format or protocol. For example, you might prefer to read...

• email or web-based discussion groups with an NNTP client because NNTP clients are usually very good at threading, tracking, automatic scoring, flagging, kill-filing, and other power discussion-group features.
• email or NNTP discussion groups in a web browser so that you can easily make a link to a message using an http:// URL. (If imap:// and news:// URLs were more widely supported, you could do this with any email and NNTP messages too.)
• RSS/XML feeds with your email client because then these messages are integrated into your email environment and an interesting message can easily be flagged, forwarded to a friend, or saved to a relevant mailbox.

What to Look OUT For in an IMAP Service Provider

In addition to looking for the things listed in the next section, I suggest that you be wary of a provider who . . .

1. does not support multiple IMAP-accessible mailboxes (aka folders) for a single user and instead only supports IMAP access to a user's INBOX. For a discussion about this, see the thread Which Hosts Are Able To Offer IMAP Subfolders? at WebHostingTalk.com, which includes this conversation snippet:

   "If a host provides the IMAP service, then you should be able to make subfolders."
   Agreed.

   And I also agree. If a provider only provides IMAP access to the INBOX, it should probably not even be called an IMAP service provider!
   
   
2. munges the body of messages that pass through their SMTP server. For example, as discussed here, Critical Path rewrites URLs that occur in incoming messages so that the URL is deflected through the Critical Path HTTP server. This is an egregious invasion of privacy! Note that I think that it is acceptable for a provider to munge a message in order to defang or remove a virus.
   
   
3. uses a virus scanner that sends auto-notification to forged From: headers (thus polluting the Net even more) or to you, the intended recipient of the virus (thus polluting your mailbox).
   
   
4. uses a phrase such as “100-percent effective” or “patent pending” or “proprietary technology” or “spam free” in the description of their service. These are clues that the provider does not understand the organic nature of spam, viruses, and of the Net in general. Examples of providers who use these phrases are:
   
   1. SpamArrest.com, which uses the first phrase here and the second phrase at the bottom of almost every page on their site. They confirmed their cluelessness by sending spam to advertise their “anti-spam solutions”! For more about this, see
      • Declan McCullagh's Politech (politechbot.com): Articles about the SpamArrest-is-spamming saga -- these articles include commentary from many knowledgeable -- and useful! -- spam fighters
      • SpamArrest Is A Spammer! by David Beckemeyer
      • SamSpade.org: SpamArrest is Spamming by Steve Atkins
      • BroadbandReports.com: When Anti-Spammers Spam: 'Spam Arrest ' sending e-mail sales pitch
      • Spamhaus Block List: SBL Advisory SBL6866
      • AVNonline.com: Spam Fighter, Heal Thyself? by Charles Farrar
      • Spam Arrest: Busted by Carl Bussjaeger (17 February 2003)
      • groovymother.com: Revenge is a dish best served with spam
      • Seattle Times: Messages earn first Spam-of-the-Year award by Charles Bermant (discusses both SpamArrest.com and Mailboxfilter.com, another supposed spam fighter who spams)
        
      More evidence of SpamArrest.com's style (or lack of it) is in this press release where their president and CEO, Brian Cartmell, says "Hormel is acting like a corporate crybaby."
      
      
   2. Mailblocks.com is an IMAP provider that I describe above. They confirmed their cluelessness by filing lawsuits against other spam-fighting companies (including their fellow “spam-fighter” Spam Arrest!). For more about this, see Spam foe puts his own interests first by Mike Langberg at SiliconValley.com.
      
      
   3. FuseMail.com, which is in The List above, uses the phrase “Block 100% of Spam and Viruses” on their front page.
   
   
5. * has no bandwidth or space limits. If a provider does not have these limits, it means either 1) they are inexperienced;  2) they are going to pull a “bait & switch” on their users; or 3) their system is going to crash & burn and take your messages down with it. For more about this, see
   • Why bandwidth matters at FastMail.FM
   • New Cornell U. System Will Meter Network Use and Charge for 'Extreme' Amounts at The Chronicle of Higher Education and the slashdot discussion about this
   • Web Hosts Routinely Offering 300+ MB Packages at Low Rates May be Ripping You Off! at FutureQuest.net.
     
   Note that extremely well funded providers such as Google and Microsoft can probably successfully offer services with very high bandwidth or space limits.
   
   
6. uses a turnkey system such as cPanel or Ensim. Sometimes this means that the people running the system are not very technically savvy.
   
   
7. does not have a web page describing the technical details of their system and the tools that they use. Sometimes this means that the people running the system are not very technically savvy.
   
   
8. rolls their own mail tools, rather than using established tools that have been used, tested, and debugged by many users on many systems. This is especially worrisome if their home-brewed mail tools are closed source and thus not open to scrutiny — and bug fixing & feature enhancement — by the collective eyes of the Net.
   
   
9. ‡ only supports SMTP authentication using the flaky and obsolete LB4S (Login-Before-SMTP) rather than the more robust SMTP AUTH. LB4S is also known as Login-Before-Send, POP-before-SMTP, POP AUTH, and DRAC (Dynamic Relay Authorization Control). To learn more about LB4S, see POP before SMTP support at mozillaZine and the discussion about SMTP relaying at EmailThatWorks.net. Note that I think it is fine if a provider offers both LB4S and SMTP AUTH.
   
   
10. supports IMAP over SSL, but
    • either charges more for it than plain (non SSL wrapped) IMAP access,
    • or their documentation does not describe how to set up IMAP clients to do IMAP over SSL.
      
    Either of these are a clue that the provider does not care about protecting their users and their system from password sniffers and man-in-the-middle attacks. SortOnce.com (in table above) is an example of a provider that charges more for IMAP over SSL.
    
    
11. has an IMAP server named pop.domain.name. This is a clue that the provider might have a POP rather than an IMAP mindset.
    
    
12. talks about “your mailbox” instead of “your mailstore” or “your mailboxes” — this is a clue that the provider has a POP rather than IMAP mindset. The words mailbox and mailstore are defined in the Terminology section above.
    
    
13. has customized their system so much that it is difficult for them to upgrade. I think that this is the reason that Eskimo.com, which I discuss in The List above, used very old software until Summer 2004.
    
    
14. has set up their outgoing SMTP server so that when it has a problem sending an outgoing message, it tries to contact the target SMTP server for only a short amount of time and then gives up and bounces the message back to the sender. An example of such a provider is enom.com, which tries for only 2 hours as discussed in the EmailDiscussions.com thread FastMail Outage - Enom Caused Lost Mail. Note that this is only relevant if you use the provider's SMTP server for sending, auto-replying, re-routing or forwarding mail.
    
    
15. § uses NFS because NFS is notoriously problematic when file locking is needed. If you might ever want to use a mailbox format that requires locking, for example traditional Unix mbox format or c-client MBX format, make sure you get a provider that does not use NFS. For more about this, see my 2004-June-23 message in comp.mail.misc.
    
    
16. has a domain name that contains the string spam. This means that they are vulnerable to being sued by Hormel Foods, which is what happened to SpamArrest.com (details in the press release SPAMARREST LLC TELLS HORMEL FOODS CORPORATION TO CAN ITS TRADEMARK CHALLENGE). This could also be a clue that the provider is not in the email business for the long haul and instead is trying to cash in on the current spam problem. For an example of a provider that had the string spam in their domain name and no longer exists, see the history of spamfree.net at archive.org. Also see Hormel Attacking Anti-Spam Trademarks? at NuclearElephant.com.
    
    
17. is involved in a lawsuit. An example of such a provider is CI Host, which is in The List above (with warnings) and was discussed at Slashdot.org on 2003 August 25. Note especially the Slashdot comment titled CI Host's Better Business Bureau Rating. Also see the previous item (#16).

What to Look For in an IMAP Service Provider

In addition to looking out for the 17 things listed in the previous section, I suggest that you look for the 54 things listed in this section. I've put the ones that are the most important to me at the top but, of course, your requirements may be different from mine.

#1: No Auto-Deletion of Messages Unless Requested by User

1. No automatic deletion of messages, unless
   • either a user explicitly requests this (for example, for a particular address);
   • or the mail was sent through an open relay, open proxy server, or other server that is known to be a spam source, in which case it should be rejected with an informative SMTP-level failure notice that is sent back to the sender so that the sender will know that their message was not delivered and that they need to fix their SMTP server.

For more about this growing problem, see:

• Melvyn Hiscock's 19-July-2003 message to uk.music.guitar with the Subject A little research needed in which he describes problems that some people have sending him email “due to my surname being considered pornographic!”
  
  
• Neil Gaiman, creator/writer of monthly cult DC Comics horror-weird series, Sandman, on the risks of unintelligent email filtering in Declan McCullagh's Politech (2003 March 27)
  
  
• News: False Spam Reports Block 15% of Permission Emails which includes this statement: “ISP spam filters are blocking out an average of 15% of legitimate email.”
  
  
• Lisa M. Bowman's Hotmail clean-out catches members out at CNET News.com, which includes this:  “Zajc, who had saved the messages in her Hotmail SENT file, logged on to find that her e-mails had evaporated into thin air. "I literally broke down in tears," said Zajc.”
  
  
• The EmailDiscussion.com thread Easiest to use email provider?, where ReuvenNY said “I learned about their [AOL's] practice of deleting your read email from the Inbox the hard way. Before I had an IMAP account with FastMail, when I traveled to Europe, I emailed to my wife's AOL account some important data I had to check periodically. To my surprise, after several days it just disappeared! If I didn't hate AOL then - that's what broke the camel's back.” (2003 May 5)
  
  
• Steve Outing's I'm Sick and Tired Of Spam (Filters) at EditorAndPublisher.com (2002 July 31)
  
  
• Brian Livingston's The e-mail scandal at InfoWorld.Com (2002 November 25)
  
  
• Paul Myers' TalkBiz News/Business Success Chronicles Special Issue about You HAD mail!, which includes these sub-sections:
  • Alert for Free Email Service Users
  • The Main Event: You HAD mail!
    
    
• Edward W. Felten's Keystone SpamKops (2002 August 16) and all his entries in FREEDOM TO TINKER > Topic: Spam
  
  
• Why the SpamCop blocking list is harmful by Jeremy Howard of FastMail.FM
  
  
• David Berlin's articles at ZDNet Tech Update:
  • The hidden gotcha of spam (2002 October 31)
  • Why spam could destroy the Internet (2002 November 14)
    
    

53 More Things to Look For

The next things that I look for when choosing an IMAP provider are the following.

2. Daily or more backups, long archival of backups, and willingness to do restores for a reasonable fee when a restore is needed because of user error. Because Pair.com (in table) will not do restores (see #17), I do not recommend Pair.com as an IMAP host. Contrast this with:
   • viaVerio.com (discussed above): tools so customers can do restores from the /backup directory themselves (search page for  Restore File utility) and getback - Restoring Files from Backup
   • Panix (discussed above): How to recover a lost file
   • Tuffmail (discussed above): What is your backup procedure? and Can you recover mail that has been deleted?
   • MailSnare.net (discussed above): Backup & Restore Q&A's in the General Information section of their FAQ
   • FastMail.FM (discussed above): How can I get a folder restored from the server backup?
   • DreamHost.com (discussed above): hourly, nightly, and weekly backups in ~/.snapshot directory (Warnings: As of 2005-March-23, DreamHost does not back up a user's junk mailbox, which is a problem when there is a non-spam message in the junk mailbox, i.e., a false positive. As of 2005-May-13, DreamHost does not back up a user's SpamAssassin settings.)
   • Lux Scientiae (discussed above): Data Backups (includes IMAP metadata)
   • IMAP partners (discussed above): FAQ: Do you do backups?
   • Runbox (discussed above): thread about Backup in the EMD Runbox forum
   • GSP.com: Backup Services in their Favorite Asked Questions
   • Sonic.net: Mail Snapshots and Retrieving files from snapshots
   • monkey.org: 2.5: what about backups?
   • myacen.com virtual and reseller hosting
   • Interland.net's (very expensive) Data Recovery Service Plan
   • musc.edu, where users can Get deleted e-mail using their emergency backup IMAP server
   • Brandeis University, where a user of their IMAP servers can “redeliver up to seven days' worth of mail by yourself”
   • MyUW.net: Backup and Restoration of Email Folders and Other User Files
   
   Even if your service provider claims that it does backups and restores, it is still a good idea for you to do your own backups. For more about this, see:
   • HawkWings.com: Gmail user gets kneecapped (2006 March 14)
   • infosecuritymag.com: Hacked Hosting Firms Caught Without Recent Backup by Keith Regan (12 May 2003)
   • news.bbc.co.uk: Anger over web hosting hitches (3 June 2003) and Hacker causes havoc for websites (24 April 2003). Bargainhost.co.uk uses cPanel and states on this page that they do backups. This makes me wonder if every cPanel system has a vulnerable backup system.
   • CNET News.com: Victims of lost files out of luck by Lisa M. Bowman
   • [Bad] Experience with MediaTemple as a Webhost by Jason Perkin
   
   Important:  If you use IMAP keywords (aka user-defined flags or labels) or any IMAP metadata, find out if your provider backs up and restores this metadata. Many providers that use Cyrus IMAP, for example MailSnare.net and FastMail.FM, do not restore all the IMAP metadata, especially the \SEEN flag. This is another reason to do your own backups!
   
   
3. Employees and owners who use IMAP themselves and take advantage of some power IMAP features. You can find out about this by sending an email message to the contact address for the provider and ask if the person who reads your message uses IMAP. If the answer is no or “what's IMAP?”, ask to be put in touch with someone in the company who uses IMAP. Then engage them in a conversation about IMAP and ask them why they use IMAP, what they like about it, what IMAP client they use, what they think are the advantages and disadvantages of IMAP compared to POP, etc. I think that the main reason that Fastmail.FM (see above) is so successful is that the owners, Jeremy Howard and Rob Mueller, are keen IMAP users and the reason they created FM was to satisfy their IMAP needs.
   
   
4. The option to point the DNS MX record of your domain at the provider's mail exchange server (aka MXer). This is known as “domain hosting” or “MX hosting” and it is essential if you want robust SMTP-level spam filtering for your domain's incoming mail.
   
   Tip: Some IMAP providers offer both email and web domain hosting, but I recommend that you get an IMAP provider whose focus is email hosting and host your domain's web site (e.g., DNS A record) with a provider whose focus is web hosting. For more about separating email and web hosting, see my blog item titled Use a Different Provider for Internet Access, Email Services, and Web Hosting.
   
   
5. Option to use the provider's server-side and frequently-updated virus- & spam-detection tools such as MailScanner, greylisting , or SpamAssassin, and if a user chooses to use these, give the user the option to set her own configurartion preferences. For example, each user at pair.com (in table above) can customize SpamAssassin via her ~/.spamassassin/user_prefs file. For details about the pair.com setup, see pair Networks - E-Mail - Junk E-Mail Filtering: Advanced Options.
   
   
6. Built-in support for server-side “greenlists” or “accept lists” that users can use for reverse spam filtering. It is especially useful if a user has the option to:
   
   • upload a pre-existing greenlist (Bluebottle supports this)
   • automatically populate the greenlist with email addresses that are in address books and “SENT” mailboxes (FastMail.FM uses your address book as your greenlist)
   • create a Subject string or a recipient address string that will be automatically greenlisted (FastMail.FM lets users do this by setting a secret word)
   
   Bluebottle (in table), FastMail.FM (in table), Runbox (in table), MailSnare (in table), Mailshell (in table), Lux Scientiae (in table), and most providers who use the Horde/IMP webmail client, are examples of providers that have built-in support for a greenlist. Note that Bluebottle and Mailshell calls these “Approved Senders,” FastMail.FM calls this a Whitelist, Lux Scientiae splits this concept into “Legitimate Lists” (for subscribed mailing lists) & a “White-List,” Pair.com calls these “Accepted Addresses,” Hotmail calls this a “Safe List,” and Outlook 2003+ calls these “Trusted Senders.”
   
   For more about this, see my blog item titled Server-Side Address Books and Server-Side Greenlists.  
   
   
7. If you choose to have messages tagged with a spam score, one of the keys to dealing with them is to be able to sort (order) the messages in your 'MaybeSpam' mailbox by spam score. This way the non-spam messages -- which should have low or no spam scores -- will bubble to the top of the sorted-by-spam-score mailbox. One way to do this is to have the spam score injected into the beginning of the Subject of each message and then use your mail client to sort the mailbox by Subject. For example, I do this in SpamAssassin by including the following in my SA user_prefs file:

   rewrite_header Subject {_SCORE(0)_}

   I recommend that you choose a provider who gives you the option of putting the spam score in a field that can be sorted on by your mail client. FastMail.FM (in Table) and Tuffmail.com (in Table) are examples of providers who give each user the option to inject the spam score into the Subject. If your provider lets you edit your SpamAssassin user_prefs file, see  man Mail::SpamAssassin::Conf for details about SpamAssassin configuration options.
   
   
8. User-configurable server-side processing of messages, using, for example, the standards-track Sieve (see RFC 3028 and 3028bis) or Procmail. Then users have the option to build their own greenlist and other reverse spam filters. FastMail.FM (in Table), TuffMail.com (in Table), and Loftmail (in List) are examples of providers who offer server-side Sieve filters.  I am collecting Sieve-related links at del.icio.us / Deflexion.com / Messaging / Sieve.
   
   
9. Refuse to send your password in plain text by accessing IMAP servers and web-based IMAP clients using either . . .
   
   1. CRAM-MD5, DIGEST-MD5, KERBEROS, GSSAPI or SPNEGO, or another secure authentication mechanism, or
   2. TLS/SSL (Transport Layer Security/Secure Sockets Layer), which encrypts the entire session, including authentication and data transfer.
      
   It is best if the server is set up so that plaintext password authentication is not allowed. This way you can't accidentally send your password in the clear. If your provider does not support secure IMAP, complain. And be assured that it will not be the first time they hear this complaint.
   
   
10. If the provider gives Unix shell access, make sure that you can connect using SSH, preferably SSH2, which offers substantially greater security than SSH1. Note that if your provider supports SSH and does not support one of the secure IMAP mechanisms that I describe in the previous item, you can use ssh port forwarding to secure your IMAP connection. (Note that the old protocols for accessing a Unix shell — rlogin, telnet, and rsh — are dead and you can visit their graves here.)
    
    
11. If you want to be able to transfer data using a protocol other than IMAP, make sure you can do this securely using, for example, WebDAV, SFTP, FTP over SSH2, or FTPS (FTP over SSL/TLS).
    
    Note that the following IMAP providers offer WebDAV: Dreamhost.com (in table), Imeme.net (in table), Mac.com (in table), indoglobal.com, OEone.net, SpyMac.com, TextDrive.com, and zettai.com (the last five are in The List).
    
    
12. Lots of disk space and low one-time fees for additonal disk space. FastMail.FM (discussed above) and Mailsnare (discussed above) are examples of providers who charge a one-time fee for extra disk space.
    
    
13. Redundant servers so that hardware or software upgrades can be done with minimal down time.
    
    
14. Support of subaddresses that can be used to have incoming messages delivered directly to specific mailbox based on the subaddress. Subaddressing is also known as “plus addressing,”   “user-extension addressing,”  & “detailed addressing” and is discussed on the following pages:
    
    
    • George Spain's Advanced IMAP E-mail Features
    • Eli Pogonatus's Email Addressing FAQ (How to use user+box@host addresses)
    • Jari Aalto's Procmail Tips in the section 11.2 Using plus addressing foo+bar@address.com
    • TMDA.net: FAQ 3.5. What is recommended for RECIPIENT_DELIMITER, `-' or `+'? and TMDA Pre-Configuration
    • My del.icio.us bookmarks about plus addressing
    
    With subaddressing, you get infinitely many email addresses for a single user ID. Depending on the provider, you may be able to use these addresses as disposable email addresses (DEA), which means that you have the option to “kill” an address once it becomes a spam repository (i.e. have all messages that are sent to it automatically rejected during the SMTP handshake).
    
    Note that the term “plus addressing” is a misnomer because some MTAs, for example the Courier and the qmail MTAs, use a dash (-) instead of a plus (+) as the recipient delimiter. FastMail.FM (discussed above) and Tuffmail.com (discussed above) are examples of providers who let their users use subaddresses that can be used to have incoming messages delivered directly to different mailboxes based on the subaddress. Also see the thread titled plus-addressing at EMD.
    
    
    

    Subaddressing Tips

    Subaddresses are especially useful for signing up for mailing lists, transactional services (banking, shopping, etc.), RSS-to-mail services, or any service where you want to be able to easily track (and possibly filter or reject) mail from a particular entity. If you use subaddresses, do not use the base address for anything important because it will be easily guessable (“de-plussed”) by spammers & spambots, and will become a junk repository. If you want to use a lot of plus addresses, choose a system that will automatically deliver a plus-addressed message to the subaddress mailbox if the subaddress mailbox already exists. On some systems you need to create a filter and a target mailbox for each plus address, which can be quite a chore if you use a lot of plus addresses. FastMail.FM and TuffMail.com are examples of systems that automatically file plus-addressed messages if the subaddress target mailbox exists. If the target mailbox does not exist, the message is filed in the INBOX. In my Procmail Quick Start, I have a tip about using Procmail to route solicited bulk email (mailing-list messages) to appropriate plus addresses on a remote system.

    
    
    
15. If you can't get subaddressing (previous item), the next best thing is a personal subdomain so that you can use infinitely many addresses @your.personal.subdomain. Depending on the provider, you may be able to use these addresses as disposable addresses.
    
    For example, FastMail.FM Members⁺ (but not free Guest accounts) and all endjunk.com, f2o.org, Mailshell.com, MailSnare.net, TuffMail.com, and Panix.com users are able to receive mail sent to anything@username.fastmail.fm, anything@username.f2o.org, anything@username.mailshell.com, anything@username.mailsnare.net, anything@username.tuffmail.com, and anything@username.users.panix.com, respectively.
    
    
16. If you can't get subaddressing or your own subdomain (see previous two items), the next best thing is an old-fashioned alias. Depending on the provider, you may be able to use an alias address as a disposable address. For more about why aliases are useful, see While Signing Up: Choosing Your Username, Domain Name, Aliases, and More below.
    
    
17. Message headers that record original envelope addresses (including subaddresses) and how these envelope addresses got resolved, such as
    • Delivered-To:  (used at most providers who use the qmail MTA such as the viaVerio Signature account; used at Gmail and GMX)
    • X-Delivered-to:  (FastMail.FM uses this as discussed here)
    • X-Resolved-to: (FastMail.FM uses this as discussed here)
    • X-Mail-from: (FastMail.FM uses this as discussed here)
    • Envelope-To:  (used at some providers who use the exim MTA)
    • X-Envelope-To: (Tuffmail.com and Pair.com use this)
    • X-Envelope-From:
    • X-Original-To:  (used at some providers who use the postfix MTA, e.g. DreamHost and Panix.com use this; MailSnare uses this as discussed here)
    • X-Rcpt-To:
    
    These are useful because the addresses in the From:, Reply-To:, To:, and Cc: headers often do not tell the full story about where a message was sent from or to. These “envelope headers” can be used by filters -- such as Procmail, Sieve, Pine, or Mulberry filters -- to help you do reverse spam and other filtering. They are especially useful if a provider lets you use either subaddressing, a personal subdomain, or aliases (see previous three items) and you want to sort your messages based on which incarnation of your address a message was sent to. For more information about these envelope headers, see the virtual domain section of my Procmail Quick Start.
    
    
18. User-configurable server-side filters that can filter on the original envelope addresses (see previous item).
    
    
19. IMAP server and web-based mail client that support IMAP system-level flags and user-defined flags, which are sometimes called labels, categories (in Outlook 2003+ & Entourage), keywords, or tags. Keywords can be used on the following IMAP servers:
    • Courier 2.1 & later -- unlimited number of keywords; technical details are in Courier-IMAP: IMAP keywords implementation
    • Cyrus -- up to 128 (or 256?) keywords
    • Microsoft Exchange
    • Mirapoint
    • University of Washington (UW) -- up to 30 keywords per mailbox; note that MMDF and Unix-mbox formatted mailboxes require the c-client "pseudo message" in order to be able to store IMAP keywords
    • Dovecot 1.0-testNN (but not 1.0-stable as of 2005-June-16); planned for final 1.0 version
    • Isode M-Box
    • (please tell me about others)
    It is possible for a system administrator to disable IMAP keywords, so these types of servers do not necessarily support IMAP keywords. For more about IMAP keywords, see Alexey Melnikov's IETF Internet Drafts draft-ietf-sieve-imapflags-05.txt & draft-melnikov-imap-keywords-03.txt, and the 22 user-defined keywords that I use.
    
    IMAP servers that do not support keywords include Courier before version 2.1 and Mercury.
    
    IMAP clients that support keywords include Mulberry 3.1+ (up to 8 keywords), Cone (up to 9 keywords), Mozilla Thunderbird and SeaMonkey (up to 5 keywords), Pine 4.60+ (the number of keywords that Pine can use depends on the IMAP server limitations; details about setting up and using keywords in Pine are here), SquirrelMail with the appropriate plug-in, and the upcoming FastMail web-based IMAP client. If you would like to be able to use more than five labels in Mozilla or Thunderbird, please go to bugzilla.mozilla.org and vote for Bug 114656 - allow arbitrary number of labels.
    
     I am collecting keyword-related links at del.icio.us / Deflexion.com / Messaging / Keywords.
    
    
20. Server-side filter or delivery agent that is user-configurable and can set and detect system-level flags and user-defined flags (keywords). For example:
    • Sieve supports this via the imapflags extension. For an example of a Sieve script that sets a flag, see Using a MaybeSpam Mailbox at Deflexion.com
    • As discussed in this message, Double Precision's maildrop 1.6 and later supports this.
    • As discussed in Setting Keywords or Labels in the Procmail Quick Start, Procmail can be used to set flags for UW and possibly other IMAP servers.
      
    
    
21. IMAP server that can do server-side threading and sorting (ordering) of messages in a mailboxes and advertises these capabilities. To find out if an IMAP server supports these, telnet to the IMAP server and issue the CAPABILITY command. Ideally the server will announce the following three capabilities (along with STARTTLS and other useful IMAP features!).
    
    

    CAPABILITY	Means the IMAP server does...	Comment
    SORT	sorting by Date, Subject, From, Size, To, or Cc (and Arrival, which actually involves no sorting)	For technical details about both SORT and THREAD, see the IETF Internet Draft titled INTERNET MESSAGE ACCESS PROTOCOL - SORT AND THREAD EXTENSIONS by M. Crispin and K. Murchison.
    THREAD=REFERENCES	advanced threading using the References, Message-ID, and Subject headers to group “conversation threads”
    THREAD=ORDEREDSUBJECT	ordered subject threading, which sorts subjects alphabetically, groups messages with the same subject, then sorts the groups by the date of the first message of each group	This type of “threading” is useful when reference threading (see previous capability) does not work because a mailbox contains messages that have been mangled by buggy software, such as Lyris ListManager (discussed here and here), Lotus Notes, or an Exchange Server that injects the header X-Mailer: Internet Mail Service (5.5.2653.19). Note:  Courier IMAP advertises THREAD=ORDEREDSUBJECT but does not do it. If you use Pine or any c-client based tool and are having problems because of this, try adding the undocumented /loser qualifier to your mailbox specification.

    
    
    
22. Uncensored -- except for spam -- web or NNTP discussion groups where users can share tips, ask questions, etc. It's best if these are publicly accessible so people who are considering using the system can get a sense of both the system and the user community.
    
    
23. Web-based or ssh-based mail client that you can use from anywhere. For a web-based client, find out if it requires cookies, JavaScript, java, or a particular web browser. These type of requirements can be a problem when you're on the road and using someone else's machine.
    
    
24. Ability to set your From: header and Reply-To: header to any valid email address when using their outgoing SMTP server or their web- or ssh-based mail client. These different From: headers are sometimes called identities, personalities, profiles, or roles. For more about this, see the EMD threads Mail services where "From address" can be specified and change from address.
    
    Tuffmail.com (discussed above), Mailsnare.net (discussed above), and FastMail.FM (discussed above) are examples of providers that let you use any valid address in your From: header. Mailblocks (described above), AOL (described above), and MSN are examples of providers who let you change the Reply-To: header but require you to use your Mailblocks, AOL, or MSN address (respectively) in your From: header when you directly use their outgoing SMTP server.
    
    Warning: If the domain name in your SMTP MAIL FROM address has an SPF record, you need to use an SPF-acceptable SMTP server; otherwise your mail will be considered a forgery by SPF-aware tools. This is discussed in this thread at EMD. As I discuss in this item below, support for SPF is another feature to look for in an IMAP provider.
    
    
25. Ability to specify an automatic Bcc (blind courtesy copy) address in one or both of the following:
    1. your provider's web-based email client (ideally with the option to delete the Bcc address if you don't want a particular message Bcc'd)
    2. your provider's outgoing SMTP server -- this will work with any email client, local or web-based, that uses your provider's outgoing SMTP server (authenticated with your username) without you needing to explicitly specify the Bcc address in the email client
       
       
    Auto Bcc'd messages can be used for:
    • archiving a copy of all your sent messages on a different server;
    • checking that your outgoing messages are not mangled by your outgoing MTA or MSA and that they are successfully sent & delivered (at least to the auto-Bcc'd system);
    • updating a remote blue or green list via Procmail, Sieve, or another server-side filter that resides on the auto-Bcc'd system; and/or
    • other things that I discuss in my blog item titled Server-Side Sent Messages
      
      
    The Horde/IMP web-based IMAP client, which is used by many IMAP service providers, supports auto Bcc. Webmail.us (discussed above) offers BCC Archiving for an additional fee. Starting 2006 May 8, FastMail.FM (discussed above) supports auto Bcc in their web-based IMAP client. Tuffmail.com (discussed above) supports auto Bcc in both their web-based IMAP clients and their outgoing SMTP server.
    
    
26. Saved Global Search. Webmail that supports saved searches (aka smart folders), which can search some or all of your mailboxes and present the search result as a virtual mailbox. MailSnare (discussed above) and Tuffmail (discussed above) bother offer this in the Horde/IMP 4.x webmail client. FuseMail (discussed above) offers this in their webmail client and also makes these “search folders” available to any IMAP client. The FastMail.FM (discussed above) webmail client and some other mail clients supports saved search across a single mailbox, but this is not very useful if you have more than a gigabyte of messages spread across many mailboxes.
    
    
27. Global Search.  If you can't get saved searches across multiple mailboxes (previous item), the next best thing is webmail that can search across multiple mailboxes (but without saving the search conditions). Some versions of SquirrelMail support this.
    
    
28. Ability to “bounce forward” (aka redirect / resend / remail / MTA-style forward) a message when using the provider's web- or ssh-based mail client. This will allow you to, for example, update a remote blue or green list via Procmail. The FastMail.FM web client (as discussed here) and the Horde/IMP web client can do this. Pine, which can be run in an ssh window, can do this if the feature enable-bounce-cmd is set.
    
    
29. Support for shared IMAP-accessible mailboxes so that some mailboxes can be shared with specified other users. Shared mailboxes can be used for announcements, discussion groups, blogging, shared bookmarks, syndication (similar to what RSS provides), spam reporting, Help Desk tracking, and lots more. FastMail.FM Enhanced accounts (in table), Imap-Partners.net (in table), iMeme.net (in table), MailSnare.net (in table), and Tuffmail.com (in table) are examples of providers who support shared IMAP-accessible mailboxes.
    
    
30. Support for public (aka anonymous) IMAP-accessible mailboxes so that some mailboxes can be shared with the public. Public mailboxes can be used for the same things as shared mailboxes (previous item), but they are readable by anyone. I do not know of any provider who supports public IMAP-accessible mailboxes, but I'm looking!
    
    
31. If you will run Pine remotely on their system in a shell (ssh window), it is nice if they have compiled Pine so that it supports SSL/TLS and so that you have the option to use a PASSFILE. One or both of these features are useful if you want to run Pine on their system and access IMAP and NNTP servers that require authentication. As discussed in this DH Knowledge Base article, DreamHost (described above) is an example of a provider that has compiled Pine with these options.
    
    
32. Ability to securely encrypt and decrypt messages when using their web- or ssh-based client. MailSnare.net (in table) supports this in their Horde/IMP 4.x webmail client. Safe-mail.net (discussed above) supports this.
    
    
33. Ability to view .doc, .xls, and other types of attachments in their web- or ssh-based client. MailSnare.net (in table) supports this in their Horde/IMP 4.x webmail client.
    
    
34. SMTP server that speaks ESMTP and authenticates using SMTP AUTH, ideally SMTP AUTH over SSL so that your user ID & password will be encrypted. Having access to a provider's SMTP server is useful for times when you do not have access to a local SMTP server or your local SMTP server has restrictions, such as not allowing you to use any From header you want. Details about how to set up many mail clients to do SMTP AUTH is at MailOps. As I discuss in the Look OUT section above, I suggest that you be wary of providers that do not use SMTP AUTH and instead use the flaky IMAP-before-SMTP or POP-before-SMTP authentication.
    
    
35. Alternative outgoing SMTP submission port (or ports) that you can use in case your Internet access provider hijacks or blocks outbound port 25 connections. Port 2525 is often used for this. Earthlink is an example of an Internet access provider who blocks outbound port 25 connections.  (Thanks to David W.Tamkin for suggesting this item.)
    
    
36. Optional use of message authentication using DomainKeys (DK). You can learn about DomainKeys here, here, and here. ControlledMail.com, Earthlink, Gmail, Yahoo, and Sify support DomainKeys.   I am collecting DK-related links at del.icio.us / Deflexion.com / Messaging / DK.
    
    
37. Optional use of SPF.   I am collecting SPF-related links at del.icio.us / Deflexion.com / Messaging / SPF; especially useful is the 2005-July-31 article SPF loses mindshare by John R. Levine.
    
    Warning: If the domain in your SMTP MAIL FROM address has an SPF record, you need to make sure that you use an outgoing SMTP server that is acceptable to SPF — otherwise your mail will be considered a forgery by SPF-aware tools. You can use the SPF tester at DNSstuff.com, at Kitterman.com, at Pobox.com, or at Microsoft to see if the combination of your SMTP MAIL FROM address and your outgoing SMTP server will be considered a forgery by systems that do SPF checking.
    
    
38. No taglines or ads inserted in messages that you send via their SMTP server or via their web- or ssh-based mail client. Ads make it more likely that your message will be tagged as spam or "probably spam" by the recipient's mail server and that your intended recipient will never receive your message.
    
    
39. SMTP server that does not add a header that state's the sender's IP address. As discussed in this thread at EmailDiscussions.com, FastMail.FM, Hushmail.com, and possibly GoDaddy.com are examples of providers that do not add such a header. Another example is LuxSci's Anonymous Secure SMTP (discussed above). Yet another example is Horde/IMP Webmail at MailSnare.net (maybe this is generally the case with Horde/IMP?). In order for this to be useful, you need to also use an email client that does not put your IP address into a header. For example if you use Pine, you need to use version 4.51 or later and set the disable-sender feature.
    
    
40. LDAP-accessible address books that can be updated by the user. LDAP-accessible address books make it possible to use the same address book from the IMAP provider's web-based IMAP client(s) and from most desktop IMAP clients (but not Opera). LDAP does for address books what IMAP does for email messages—makes them accessible from most standards-based messaging applications. IMAP-Partners.net (in table), LuxSci.com (in table), and Tuffmail.com (in table) support LDAP-accessible address books.
    
    For more about this, see my blog item titled Server-Side Address Books and Server-Side Greenlists.
    
    
41. Support for the ManageSIEVE protocol so you can update, manage, and automatically check the syntax of your remote Sieve scripts using a program running on your desktop (for example, Mulberry). Tuffmail.com (in table) and Loftmail.com (in list) are providers that support the ManageSIEVE protocol.
    
    
42. Support for iCalendar (Internet Calendaring and Scheduling Core Object Specification, RFC 2445), iMIP (iCalendar Message-Based Interoperability Protocol, RFC 2447), and iTIP (iCalendar Transport-Independent Interoperability Protocol). Mulberry 4.0 and later, Apple's iCal, and the Mozilla Calendar Project support these protocols. MyRealBox.com, Mac.com, and TextDrive.com are examples of providers that supports the iCal protocol.
    
    
43. IMAP server and web-based IMAP clients with full read-write ANNOTATEMORE support.
    
    
44. If the provider uses UW IMAP, find out what is the default mailbox format, whether a user can use a non-default mailbox format and if so, how to do that. If you like to keep thousands of messages in a single mailbox, you'll probably want to use the efficient c-client MBX mailbox format. LuxSci (discussed above) is an example of a provider that uses MBX format mailboxes.
    
    
45. If the provider uses Courier IMAP, ask what file system they use. A Linux file system (that is not using traditional ext2 or ext3) tends to be better at handling large maildir-formatted mailboxes than a SVR4 file system. It's best if the file system has fast  open()  calls. If they don't have this type of file system, mailbox performance may be slow. For more about this, see Daniel Stone's message Re: UW IMAP hatred? (Re: Postfix Newbie questions) in mailing.postfix.users.
    
    
46. Ability to send an auto-reply to messages that are from addresses on your greenlist. This way if you decide to stop using the account, you can set it up to automatically notify green addresses about your new address.
    
    
47. Ability to cancel the account and have all messges that are sent to it automatically rejected at the SMTP level so that your correspondents will know that messages are not being delivered to that address.
    
    
48. If you host both a web site and email with a provider, it's nice if you have the option to have a different IMAP and (S)FTP password. This way if one password is compromised, the other data should still be safe.
    
    
49. If the provider has a web-based mail client, it's useful if this client can also be used to read and manage content that is syndicated (e.g., via Atom, RSS, etc.). Oddpost (discussed above), MailSnare (discussed above), and FuseMail (discussed above) are examples of providers that offer this. Geekmail does it by snarfing (via “Mailfunnel”) RSS feeds and putting them in your Geekmail IMAP INBOX, which can then be accessed via any IMAP client, including their webmail client. MailSnare presents up to 3 feeds on your Today page. Rumor: According to this 2005-April-10 EMD message, Gmail might be planning to offer this.
    
    
50. Option to read or be notified about new messages via an RSS/XML feed. For example, if you have a Google Gmail account, unread messages in your Gmail INBOX are available via a username/password-protected Atom feed at https://gmail.google.com/gmail/feed/atom. I do not know of any IMAP Service Provider that offers this -- if you do, please let me know.
    
    
51. If you like to read NNTP newsgroups, it's nice if a provider allows access to News via IMAP so you can use an IMAP client, such as Mulberry, to read newsgroups. If you know of a provider that has this set up or a site that describes how to set this up, please let me know!
    
    
52. Located in a country that does not have privacy-invasion laws such as the proposed European Parliament anti-terrorism law or what is described in the article All emails to be logged and stored for six months under new Swiss law.
    
    
53. Emergency status page that is located on an entirely different network. For example, FastMail.FM (discussed above) uses status.fastmail.fm and the FM forums at EmailDiscussions.com, DreamHost (discussed above) uses dreamhoststatus.com, and HostingMatters.com (discussed in this section above) uses gandalf.hmdnsgroup.net/nagios/.
    
    
54. Access to an IMSP (Internet Message Support Protocol) server so you can store your configuration files, address books, and bookmarks (Cyrusoft is planning support for IMSP bookmarks) on the server and access them from any system that supports IMSP. Note that ACAP (Application Configuration Access Protocol), which was supposed to be a replacement for IMSP, is dead. As Cyrus Daboo said in this 2003-June-19 message to the mulberry-discuss mailing list, “Don't use ACAP, use IMSP instead.”
    
    

For more about features to look for in a provider, see

• Omar Shahine's IMAP services instead of .Mac at TidBITS Talk
• Lukas Koster's A Short Guide to Free Email
• Jeff Petry's Top 10 Tips Before Choosing a Web Host at HostSearch.com
• obfuscated's Finding a hosting company (how-to guide) in forums.webhostdir.com