gnu Mailutils contains a series of useful mail clients, servers, and libraries. These are the primary mail utilities of the GNU system. Specifically, this package contains a POP3 server, an IMAP4 server, and a Sieve mail filter. It also provides a POSIX `mailx' client, and a collection of other tools. The central library is capable of accessing different mailbox formats and mailers as well as off of local or remote POP3 and IMAP4 servers.
This software is part of the GNU Project and belongs to the Free Software Foundation. All libraries are licensed using the GNU LGPL. The documentation is licensed under the GNU FDL, and everything else is licensed using the GNU GPL.
This package started off to try and handle large mailbox files more gracefully then current POP3 servers did. While it handles this task, it also allows you to support a variety of different mailbox formats without any real effort on your part. Also, if a new format is added at a later date, your program will support that new format automatically as soon as it is compiled against the new library.