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.

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.

notifymuch displays desktop notifications for messages in the notmuch database. The notifications are sent using libnotify to a notification daemon. The query to find messages to send a notification about is configurable, and a notification for the same message will not be send within a configurable period (defaults to 48 hours). To use notifymuch, run notifymuch after new mail is indexed, this can be automated by invoking notifymuch from the post-new hook.

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.

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

TNEF is a tar-like program that unpacks MIME attachments of type application/ms-tnef.

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

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

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)

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.

Bogofilter is a mail filter that classifies mail as spam or ham (non-spam) by a statistical analysis of the message's header and content (body). The program is able to learn from the user's classifications and corrections. It is based on a Bayesian filter.

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.

Alot is a terminal-based mail user agent based on the Notmuch mail indexer. It is written in Python using the urwid toolkit and features a modular and command prompt driven interface to provide a full mail user agent (MUA) experience as an alternative to the Emacs mode shipped with Notmuch.

fdm fetches and delivers mail in various ways.

Mail may be fetched from IMAP or POP3 servers, from local maildirs, or read from standard input. It is then filtered based on regular expressions, its size or age, or the output of a (shell) command. It can be rewritten by an external process, dropped, left on the server or delivered into maildirs, mboxes, to a file or pipe, or any combination.

fdm is primarily designed for use by a single user, but can use privilege separation to safely deliver mail in multi-user setups.

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

DKIMproxy is an SMTP proxy that signs and verifies Internet mail using the Mail::DKIM Perl module. It comprises two separate proxies: an outbound proxy for signing outgoing email, and an inbound proxy for verifying signatures of incoming messages.

It was designed for Postfix, but can be used to add DKIM support to nearly any existing mail server. With Postfix, the proxies can operate as either Before-Queue or After-Queue content filters.

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

Mail::SPF is the Sender Policy Framework implemented in Perl.

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.

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.

MHonArc is a Perl mail-to-HTML converter. MHonArc provides HTML mail archiving with index, mail thread linking, etc; plus other capabilities including support for MIME and powerful user customization features.

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.

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.

public-inbox implements the sharing of an email inbox via Git to complement or replace traditional mailing lists. Readers may read via NNTP, IMAP, Atom feeds or HTML archives.