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.

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.

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 Procmail is considered stable, but is no longer maintained.

A schema-driven command line tool for administering Stalwart Mail and Collaboration Server over its JMAP API.

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.

The purpose of this mail library is to provide a portable, efficient framework for different kinds of mail access: IMAP, SMTP, POP and NNTP. It provides an API for C language. It's the low-level API used by MailCore and MailCore 2.

Technology for Resting Email Encrypted Storage (TREES) is a NaCL-based Dovecot encryption plugin. This plugin adds individually encrypted mail storage to the Dovecot IMAP server. It is inspired by Posteo's scrambler which uses OpenSSL and RSA key pairs. TREES works in a similar way, but uses the Sodium crypto library (based on NaCL).

How it works:

1. On IMAP log in, the user's cleartext password is passed to the plugin.

2. The plugin creates an argon2 digest from the password.

3. This password digest is used as a symmetric secret to decrypt a libsodium secretbox.

4. Inside the secretbox is stored a Curve25519 private key.

5. The Curve25519 private key is used to decrypt each individual message, using libsodium sealed boxes.

6. New mail is encrypted as it arrives using the Curve25519 public key.

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

Mumi is a Debbugs web interface.

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

Exim is a message transfer agent (MTA) developed at the University of Cambridge for use on Unix systems connected to the Internet. In style it is similar to Smail 3, but its facilities are more general. There is a great deal of flexibility in the way mail can be routed, and there are extensive facilities for checking incoming mail.

Notmuch is a command-line based program for indexing, searching, read- ing, and tagging large collections of email messages.

This Python module can be used to generate and parse RFC 5451/7001/7601 Authentication-Results email headers. It supports extensions such as:

• RFC 5617 DKIM/ADSP

• RFC 6008 DKIM signature identification (header.b)

• RFC 6212 VBR

• RFC 6577 SPF

• RFC 7281 Authentication-Results registration for S/MIME

• RFC 7293 The Require-Recipient-Valid-Since header field

• RFC 7489 DMARC

• ARC (draft-ietf-dmarc-arc-protocol-08)

Guile is the GNU Ubiquitous Intelligent Language for Extensions, the official extension language of the GNU system. It is an implementation of the Scheme language which can be easily embedded in other applications to provide a convenient means of extending the functionality of the application without requiring the source code to be rewritten.

GNU Binutils is a collection of tools for working with binary files. Perhaps the most notable are "ld", a linker, and "as", an assembler. Other tools include programs to display binary profiling information, list the strings in a binary file, and utilities for working with archives. The "bfd" library for working with executable and object formats is also included.

Guile is the GNU Ubiquitous Intelligent Language for Extensions, the official extension language of the GNU system. It is an implementation of the Scheme language which can be easily embedded in other applications to provide a convenient means of extending the functionality of the application without requiring the source code to be rewritten.

Binaries used to bootstrap the distribution.

Headers of the Linux-Libre kernel.

Tarballs containing all the bootstrap binaries

Guile is the GNU Ubiquitous Intelligent Language for Extensions, the official extension language of the GNU system. It is an implementation of the Scheme language which can be easily embedded in other applications to provide a convenient means of extending the functionality of the application without requiring the source code to be rewritten.

XMLtoMan and XMLMantoHTML are two small scripts to convert xml to man pages in groff format or html. It features the usual man page items such as description, options, see also, etc.

This package provides excerpts from the POSIX.1-2008 and TC1 standards (collectively, POSIX.1-2013) in manual page form. While the Linux man-pages project documents the system as it exists on Linux- and glibc-based systems, this package documents the portable software API as nominally implemented by many Unix-likes.

qman is a modern, full-featured manual page viewer featuring hyperlinks,web browser like navigation, a table of contents for each page, incremental search, on-line help, and more. It also strives to be fast and tiny, so that it can be used everywhere.

Features:

• Index page that displays all manual pages available on the system, sorted alphabetically and organised by section

• Pages for apropos and whatis results

• Hyperlinks to other manual pages

• Hyperlinks for URLs and email addresses

• Hyperlinks to files or directories in the local filesystem

• In-page hyperlinks

• A table of contents for each manual page

• Incremental search for manual pages

• Incremental free page text search

• Command-line options similar to those of man (most importantly, -k and -f)

• Keyboard mappings similar to those of less

• Mouse support

• Navigation history

• On-line help

• Fully configurable using INI-style config files

• Manual page

This package provides traditional Unix "man pages" documenting the Linux kernel and C library interfaces employed by user-space programs.