GMime provides a core library and set of utilities which may be used for the creation and parsing of messages using the Multipurpose Internet Mail Extension (MIME).

This is an address lookup tool using a Notmuch database, useful for email address completion.

The filter-dkimsign OpenSMTPd filter signs outgoing e-mail messages with DKIM (RFC 4871).

This package provides a TNEF stream reader library and related tools to process winmail.dat files.

Swaks is a flexible, scriptable, transaction-oriented SMTP test tool. It handles SMTP features and extensions such as TLS, authentication, and pipelining; multiple versions of the SMTP protocol including SMTP, ESMTP, and LMTP; and multiple transport methods including unix-domain sockets, internet-domain sockets, and pipes to spawned processes. Options can be specified in environment variables, configuration files, and the command line allowing maximum configurability and ease of use for operators and scripters.

Claws-Mail is an email client (and news reader) based on GTK+. The appearance and interface are designed to be familiar to new users coming from other popular email clients, as well as experienced users. Almost all commands are accessible with the keyboard. Plus, Claws-Mail is extensible via addons which can add many functionalities to the base client.

Email::Abstract provides module writers with the ability to write simple, representation-independent mail handling code.

Email::Address implements a regex-based RFC 2822 parser that locates email addresses in strings and returns a list of Email::Address objects found. It is recommended to use Email::Address::XS instead.

neatmail is a noninteractive mail client. It generates a listing of the messages in a mailbox in mbox format and executes a list of ex-like commands on it.

smtpmail is a little console-based tool for users who have no local mailserver on their machine. It enables these users to send their mail over a remote SMTP server.

This package provides Python bindings to use the Notmuch mail indexing and search library.

Mu is a tool for dealing with e-mail messages stored in the Maildir format. Mu's purpose in life is to help you to quickly find the messages you need; in addition, it allows you to view messages, extract attachments, create new maildirs, and so on.

Email::Address::XS implements RFC 5322 parser and formatter of email addresses and groups. Unlike Email::Address, this module does not use regular expressions for parsing but instead is implemented in XS and uses shared code from Dovecot IMAP server.

Nullmailer is a simple replacement MTA for hosts that receive no local mail and only relay mail to a fixed set of smart relays. It's useful for systems such as Web servers that must be able to send email notifications, without having to run a full-blown MTA such as sendmail or qmail.

Nullmailer is designed to be simple to configure, easy to extend, and secure. It requires little ongoing administration. The included sendmail emulator front-end should allow most (if not all) sendmail-compatible programs to run without any changes.

ripMIME is a small program to extract the attached files out of a MIME-encoded email package.

Procmail is a mail delivery agent (MDA) featuring support for a variety of mailbox formats such as mbox, mh and maildir. Incoming mail can be sorted into separate files/directories and arbitrary commands can be executed on mail arrival. Procmail is considered stable, but is no longer maintained.

The Libpst utilities include readpst which can convert email messages to both mbox and MH mailbox formats, pst2ldif which can convert the contacts to .ldif format for import into LDAP databases, and other tools to process Outlook email archives.

Email::Sender replaces the old and sometimes problematic Email::Send library.

Mailman3 allows emails sent to its mailing lists to be archived by any software provided that there is a plugin (loadable by Mailman3) designed to communicate with it properly. This module contains a Mailman3 archiver plugin which sends emails to HyperKitty, the official Mailman3 web archiver.

Fetchmail is a full-featured, robust, well-documented remote-mail retrieval and forwarding utility intended to be used over on-demand TCP/IP links (such as SLIP or PPP connections). It supports every remote-mail protocol now in use on the Internet: POP2, POP3, RPOP, APOP, KPOP, all flavors of IMAP, ETRN, and ODMR. It can even support IPv6 and IPSEC.

Fetchmail retrieves mail from remote mail servers and forwards it via SMTP, so it can then be read by normal mail user agents such as mutt, elm or BSD Mail. It allows all your system MTA's filtering, forwarding, and aliasing facilities to work just as they would on normal mail.

Email::Simple provides simple parsing of RFC 2822 message format and headers.

This package provides a CLI application to execute scripts on IMAP mailbox changes (new/deleted/updated messages) using IDLE and it is mostly compatible with the configuration of imapnotify made with Python.

This project is a reimplementation of the Python stdlib smtpd.py based on asyncio.

bubger is a mailing list archive generator for mail stored in IMAP. It produces static files of HTML, Atom and mboxrd, making its output easy to serve from a host without IMAP access. It requires the IMAP THREAD extension.