NeoMutt is a command-line mail reader which is based on Mutt. It adds a large amount of new and improved features to Mutt.

Email::MIME is an extension of the Email::Simple module, to handle MIME encoded messages. It takes a message as a string, splits it up into its constituent parts, and allows you access to various parts of the message. Headers are decoded from MIME encoding.

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.

Urlscan is a small program that is designed to integrate with the Mutt mail reader to allow you to easily launch a Web browser for URLs contained in email messages. It parses an email message or file and scans it for URLs and email addresses. It then displays the URLs and their context within the message, and allows you to choose one or more URLs to send to your Web browser. Alternatively, it send a list of all URLs to standard output. It is a replacement for the urlview program.

bower is a curses front-end for the Notmuch email system, written in the Mercury language.

Khard is an address book for the console. It creates, reads, modifies and removes CardDAV address book entries at your local machine. For synchronizing with a remote address book, vdirsyncer is recommended. Khard can also be used from within the email client mutt.

Anubis is a daemon that sits between the Mail User Agent (MUA) and the Mail Transfer Agent (MTA). When a mail is sent by a user in the MUA, it is first passed to Anubis, which performs additional processing to the message before passing it on for delivery by the MTA. Anubis may, for example, modify the message headers or body, or encrypt or sign the message.

Mail::DKIM is a Perl module that implements the DKIM standard, and the older Yahoo! DomainKeys standard, both of which sign and verify emails using digital signatures and DNS records. Mail-DKIM can be used by any Perl program that wants to provide support for DKIM and/or DomainKeys.

This is a Python library for the generation of email authentication headers. The library can perform DKIM, SPF, and DMARC validation, and the results are packaged into the Authentication-Results header. The library can DKIM and ARC sign messages and output the corresponding signature headers.

isync/mbsync is a command-line tool for two-way synchronization of mailboxes. Currently Maildir and IMAP are supported types.

The osmtpd API is an event-based C programming interface for writing OpenSMTPd filters.

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).

GNU Mailman is software for managing email discussion and mailing lists. Both users and administrators generally perform their actions in a web interface, although email and command-line interfaces are also provided. The system features built-in archiving, automatic bounce processing, content filtering, digest delivery, and more.

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.

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.

OpenSMTPD is an implementation of server-side SMTP, with some additional standard extensions. It allows ordinary machines to exchange e-mails with other systems speaking the SMTP protocol, or to deliver them to local users.

In order to simplify the use of SMTP, OpenSMTPD implements a smaller set of functionality than those available in other SMTP daemons. The objective is to provide enough features to satisfy typical usage at the risk of unsuitability to esoteric or niche requirements.

The mailmanclient library provides official Python bindings for the GNU Mailman 3 REST API.

Postorius is a Django app which provides a web user interface to access GNU Mailman.

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

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

Pigeonhole adds support for the Sieve language (RFC 5228) and the ManageSieve protocol (RFC 5804) to the Dovecot e-mail server.

Sieve is a language for filtering incoming mail. Messages can be forwarded or sorted into separate folders. Unwanted messages can be rejected or discarded, and, when the user is not available, the Sieve interpreter can send an automated reply.

Sieve is meant to be simple, extensible, and system-independent. The intention is to make it impossible to write anything more complex (and dangerous) than simple mail filters. Unlike most other mail filtering script languages, Sieve does not allow users to execute arbitrary programmes.

Through the ManageSieve protocol, users can remotely manage their Sieve scripts without needing file system access. The server accepts only valid scripts to prevent embarrassing errors later on.

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.

IMAPFilter is a mail filtering utility. It connects to remote mail servers using IMAP, sends searching queries to the server and processes mailboxes based on the results. It can be used to delete, copy, move, flag, etc. messages residing in mailboxes at the same or different mail servers. The 4rev1 and 4 versions of IMAP are supported.

This package provides MIME type associations for file types.