Rspamd is a spam filter that evaluates email messages by a number of rules including: regular expressions, statistical analysis, and URL blacklists. Rspamd gives each message a spam score, e.g., for further processing by an MTA.

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

This package provides a tool to extract, recover and undelete email messages from Outlook Express .dbx files.

The RSS2email program (r2e) fetches RSS/Atom news feeds, converts them into emails, and sends them.

Balsa is a highly configurable and robust mail client for the GNOME desktop. It supports both POP3 and IMAP servers as well as the mbox, maildir and mh local mailbox formats. Balsa also supports SMTP and/or the use of a local MTA such as Sendmail.

Sendmail is a mail transfer agent (MTA) originally developed by Eric Allman. It is highly configurable and supports many delivery methods and many transfer protocols.

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 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

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

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

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

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.

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.

aerc is a textual email client for terminals. It features:

1. First-class support for using patches and git send-email

2. Vi-like keybindings and command system

3. A built-in console

4. Support for multiple accounts

This package takes your 48x48x1 portrait image and compresses it.

Python module that implements DKIM (DomainKeys Identified Mail) email signing and verification (RFC6376). It also provides helper scripts for command line signing and verification. It supports DKIM signing/verifying of ed25519-sha256 signatures (RFC 8463). It also supports the RFC 8617 Authenticated Received Chain (ARC) protocol.

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

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.

Mutt is a small but very powerful text-based mail client for Unix operating systems.

This module wraps MIME::Base64 and MIME::QuotedPrint.

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

Blists is a web interface to mailing list archives that works off indexed mbox files. There are two programs: bindex and bit. bindex generates or updates the index file (incremental updates are supported). bit is a CGI/SSI program that generates web pages on the fly. Both programs are written in C and are very fast.

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.

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.