dovecot-libsodium-plugin provides a libsodium password hashing scheme (such as scrypt) plug-in for Dovecot.

The hyperkitty Django app provides a web user interface to access GNU Mailman3 archives, and manage it. This interface uses django, and requires some configuration.

OfflineImap synchronizes emails between two repositories, so that you can read the same mailbox from multiple computers. It supports IMAP as REMOTE repository and Maildir/IMAP as LOCAL repository.

afew is an initial tagging script for notmuch mail. It provides automatic tagging each time new mail is registered with notmuch. It can add tags based on email headers or Maildir folders and can handle spam and killed threads.

Mlmmj is a simple and slim mailing list manager (MLM) inspired by ezmlm. It works with many different Mail Transport Agents (MTAs) and is simple for a system administrator to install, configure and integrate with other software. As it uses very few resources, and requires no daemons, it is ideal for installation on systems where resources are limited. Its features include:

1. Archive, Custom headers / footer,

2. Fully automated bounce handling (similar to ezmlm),

3. Complete requeueing functionality, Moderation functionality, Subject prefix,

4. Subscribers only posting, Regular expression access control,

5. Functionality to retrieve old posts, Web interface, Digests,

6. No-mail subscription, VERP support,

7. Delivery Status Notification (RFC1891) support,

8. Rich and customisable texts for automated operations.

This package provides tools for the conversion of Outlook Express data files to standard mailbox format.

mpop is a small and fast POP3 client suitable as a fetchmail replacement.

mpop supports multiple accounts, header based mail filtering, delivery to mbox files, maildir folders or an MDA, TLS/SSL, several authentication methods, IDN and SOCKS proxies.

Dovecot is a mail server whose major goals are security and reliability. It supports mbox/Maildir and its own dbox/mdbox formats.

The l2md command line tool imports public-inbox archives via Git and exports them in maildir format or to an MDA through a pipe.

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.

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.

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.

GNU Mailutils is a collection of programs for managing, viewing and processing electronic mail. It contains both utilities and server daemons and all operate in a protocol-agnostic way. The underlying libraries are also available, simplifying the addition of mail capabilities to new software. GNU Mailutils provides the following commands:

• dotlock

• decodemail

• frm

• from

• guimb

• mail

• mailutils

• mailutils-config

• messages

• mimeview

• movemail

• popauth

• putmail

• readmsg

• sieve

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).

nmail is an easily configurable terminal-based email client with a ncurses user interface similar to alpine and pine.

Email::Date::Format provides a means for generating an RFC 2822 compliant datetime string.

Mew (Messaging in the Emacs World) is a user interface for text messages, multimedia messages (MIME), news articles and security functionality including PGP, S/MIME, SSH, and SSL.

Sieve-connect lets you view, upload, edit, delete, and otherwise manage Sieve scripts on any mail server that speaks the ManageSieve protocol, as specified in RFC 5804.

Sieve (RFC 5228) is a specialised language for e-mail filtering. Sieve scripts are stored on the server and run whenever mail arrives. They can automatically sort new messages into folders, silently reject them, send an automated response, and more.

sieve-connect is designed to be both a tool which can be invoked from scripts as well as a decent interactive client. It supports TLS for connection privacy, as well as authentication with SASL or GSSAPI client certificates. It should be a drop-in replacement for sieveshell from the Cyrus IMAP project.

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

The sendgmail command provides a minimal sendmail-compatible front-end that connects to Gmail using OAuth2. It is specifically designed for use with git send-email. The command needs a Gmail API key to function.

Guix's version of sendgmail has been patched for compatibility with all known forks, including support for non-@gmail.com email addresses.

Email::MessageID generates recommended message-ids to identify a message uniquely.

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.

Abook is a text-based address book program designed to use with the Mutt mail client.

pan is a Usenet newsreader that's good at both text and binaries. It supports offline reading, scoring and killfiles, yEnc, NZB, PGP handling, multiple servers, and secure connections.