Fetchmail Feature List

Since 5.0:

• STARTTLS is supported in both POP and IMAP.
• ESMTP AUTH (RFC 2554) is supported.
• Has the capability of adding trace information to the Received header to faciliate mail filtering by mailserver and remote account.
• Fetchmail now has options to handle SSL certificate validation.
• Fetchmail can be told to fall back to delivering via local sendmail if it can't open port 25.
• Support for AUTH=CRAM-MD5 under POP3, a la RFC2195.
• Support for ODMR (On-Demand Mail Relay), RFC 2645.
• It's now easy to deliver mail to a local LMTP socket.
• The interface option now checks both local and remote interface IPs.
• The plugin facility has been enhanced; %h and %p options are now available to pass in the hostname and service port number.
• Added a dropdelivered option to discard Delivered-To headers. This addresses a problem with using fetchmail and postfix as a relay inside a domain; when postfix sees incoming messages with delivered-to headers looking exactly the same as the ones it adds himself, it bounces the message.
• Added --smtpname to set username and domain portion of SMTP "RCPT TO" command. <fetchmail@mail.julianhaight.com>.
• Added "from" server's IP address to inserted Received line <fetchmail@mail.julianhaight.com>.
• Fetchmail now runs on BeOS, thanks to David Reid <david@jetnet.co.uk>.
• In IMAP, unseen-message counting and indexing is now done by SEARCH UNSEEN at the beginning of each poll or re-poll (rather than with the UNSEEN and RECENT responses and FLAGS queries on individual messages). This significantly cuts down on traffic to and from the server, and gives more reliable results.
• The aka option now matches hostname suffixes, so (for example) saying `aka netaxs.com' will match not just netaxs.com but also (say) pop3.netaxs.com and mail.netaxs.com.
• Fetchmail can optionally use the RFC 2177 IDLE extension on an IMAP server that supports it. On IMAP servers that don't, it can simulate it using periodic NOOP commands.
• Fetchmail now recognizes the RFC 2449 extended responses [IN-USE] and [LOGIN-DELAY].
• Fetchmail running in daemon mode now restarts itself quietly when the rc file is touched.
• Following recent court decisions and changes in U.S. federal regulatory policy, hooks for Secure Sockets Layer (SSL) are now part of the main fetchmail distribution. The distribution still contains no actual cryptographic code.
• NTLM support under IMAP, so fetchmail can query Microsoft Exchange servers.
• Expunge option can now be used to break POP3 retrieval into subsessions.
• Support for AUTH=CRAM-MD5 under IMAP, a la RFC2195.

Since 4.0:

• The interface and monitor options now work with freeBSD.
• Fetchmail now sends RFC1894-conformant bouncemail on SMTP and LMTP errors.
• Full support for LMTP according to RFC2033.
• True multi-language support using GNU gettext.
• Support for use of HESIOD with Kerberos.
• The --bsmtp option supports recording fetched mail as a BSMTP batch.
• The --limit option can now be used in daemon mode, with oversized-message notifications being mailed to the calling user.
• Configurable support for the SDPS extensions in www.demon.net's POP3 service.
• There is now an interactive GUI fetchmail configurator, fetchmailconf.
• Code is 64-bit clean and Y2K-safe.
• Automatically decodes armored 7-bit MIME into 8 bits (this can be suppressed).
• You can specify which SMTP error is recognized as a spam block.
• Support for Kerberos V authentication.
• Support for IMAP-OTP authentication using Craig Metz's patches for UW IMAP.
• Support for IPv6
• Support for IMAP with RFC1731-conformant GSSAPI authentication.
• Fixed and verified support for Cyrus IMAP server, M$ Exchange, and Post Office/NT.
• Support for responding with a one-time password when a POP3 server issues an RFC1938-conforming OTP challenge.
• Support for Compuserve's RPA authentication protocol for POP3 (not compiled in by default, but configurable).

Since 3.0:

• Support for IMAP RFC 1731 authentication with Kerberos v4.
• Support for multiple-folder retrieval in a single session under IMAP.
• Following SMTP 571 response to a From line, fetchmail no longer downloads the bodies of spam messages.
• Support for a `hunt list' of SMTP hosts.
• Support for ESMTP 8BITMIME and SIZE options.
• Support for ESMTP ETRN command.
• The stripcr & forcecr options to explicitly control carriage-return stripping and LF->CRLF mapping before mail forwarding.

Since 2.0:

• Support for secure use with ssh.
• Mailserver passwords can be parsed out of your .netrc file.
• When forwarding mail via SMTP, fetchmail respects the 571 "spam filter" response and discards any mail that triggers it.
• Transaction and error logging may optionally be done via syslog.
• (Linux only) Security option to permit fetchmail to poll a host only when a point-to-point link to a particular IP address is up.
• RPOP support (restored; had been removed in 1.8).

2.0 and earlier versions:

• Support POP2, APOP, RPOP, IMAP2, IMAP2bis, IMAP3, IMAP4, IMAP4rev1. .
• Support for Kerberos V4 user authentication (either MIT or Cygnus).
• Host is auto-probed for a working server if no protocol is specified for the connection. Thus you don't need to know what servers are running on your mail host in advance; the verbose option will tell you which one succeeds.
• Delivery via SMTP to the client machine's port 25. This means the retrieved mail automatically goes to the system default MDA as if it were normal sender-initiated SMTP mail.
• Configurable timeout to detect if server connection is dropped.
• Support for retrieving and forwarding from multi-drop mailboxes that is guaranteed not to cause mail loops.
• Large user community -- fetchmail has a large user base (the author's beta list includes well over two hundred people). This means feedback is rapid, bugs get found and fixed rapidly.
• Carefully written, comprehensive and up-to-date man page describing not only modes of operation but also how to diagnose the most common kinds of problems and what to do about deficient servers.
• Rugged, simple, and well-tested code -- the author relies on it every day and it has never lost mail, not even in experimental versions. (In the project's entire history there has only been one recorded instance of lost mail, and that was due to a quirk in some Microsoft code.)
• Strict conformance to relevant RFCs and good debugging options. You could use fetchmail to test and debug server implementatations.
• For anybody who cares, fetchmail is Y2K safe.

Features in common with other remote-mail retrieval programs:

• Support for POP3.
• Easy control via command line or free-format run control file.
• Daemon mode -- fetchmail can be run in background to poll one or more hosts at a specified interval.
• From:, To:, Cc:, and Reply-To: headers are rewritten so that usernames relative to the fetchmail host become fully-qualified Internet addresses. This enables replies to work correctly. (Would be unique to fetchmail if I hadn't added it to fetchpop.)
• Message and header processing are 8-bit clean.