GNU Mailutils is a rich and powerful protocol-independent mail framework. It contains a series of useful mail libraries, clients, and servers. These are the primary mail utilities for the GNU system. The central library is capable of handling electronic mail in various mailbox formats and protocols, both local and remote. Specifically, this project contains a POP3 server, an IMAP4 server, and a Sieve mail filter. It also provides a POSIX `mailx' client, and a collection of other handy tools.
The GNU Mailutils libraries supply an ample set of primitives for handling electronic mail in programs written in C, C++, Python or Scheme.
At the core of Mailutils is libmailutils, a library which provides universal access to various mailboxes and protocols: UNIX mailbox, Maildir, MH, POP3, IMAP4, Sendmail, SMTP. Mailutils offers functions for almost any mail-related task, such as parsing of messages, email addresses and URLs, handling MIME messages, listing mail folders, mailcap facilities, extensible Sieve filtering, access control lists. It supports various modern data security and authentication techniques: TLS encryption, SASL and GSSAPI, to name a few. The framework is able to work with a wide variety of authorization databases, ranging from traditional system password database up to RADIUS, SQL and LDAP.
The utilities provided by Mailutils include imap4d and pop3d mail servers, mail reporting utility comsatd, general-purpose mail delivery agent maidag, mail filtering program sieve, and an implementation of MH message handling system.
All utilities share the same subset of command line options and use a unified configuration mechanism, which allows to easily configure the package as a whole.
This software is part of the GNU Project and is copyrighted by the Free Software Foundation. All libraries are distributed under the terms of the Lesser GNU Public License. The documentation is licensed under the GNU FDL, and everything else is licensed under the GNU GPL.