msmtp is an SMTP client. In the default mode, it transmits a mail to an SMTP server (for example at a free mail provider) which takes care of further delivery.

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.

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.

Mb2md is a Perl script that takes one or more mbox format files and converts them to maildir format directories.

Mailman3 allows emails sent to its mailing lists to be archived by any software provided that there is a plugin (loadable by Mailman3) designed to communicate with it properly. This module contains a Mailman3 archiver plugin which sends emails to HyperKitty, the official Mailman3 web archiver.

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.

Email::Sender replaces the old and sometimes problematic Email::Send library.

A flexible, extensible mail retrieval system with support for POP3, IMAP4, SSL variants of both, maildirs, mboxrd files, external MDAs, arbitrary message filtering, single-user and domain-mailboxes, and many other useful features. This is a fork derived from getmail 5.14, aimed at Python 3 compatibility.

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.

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.

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.

Muchsync brings Notmuch to all of your computers by synchronizing your mail messages and Notmuch tags across machines. The protocol is heavily pipelined to work efficiently over high-latency networks such as mobile broadband. Muchsync supports arbitrary pairwise synchronization among replicas. A version-vector-based algorithm allows it to exchange only the minimum information necessary to bring replicas up to date regardless of which pairs have previously synchronized.

Nullmailer is a simple replacement MTA for hosts that receive no local mail and only relay mail to a fixed set of smart relays. It's useful for systems such as Web servers that must be able to send email notifications, without having to run a full-blown MTA such as sendmail or qmail.

Nullmailer is designed to be simple to configure, easy to extend, and secure. It requires little ongoing administration. The included sendmail emulator front-end should allow most (if not all) sendmail-compatible programs to run without any changes.

Mail::AuthenticationResults parses the message header field that indicates the message authentication status as per RFC7601. This module is not fully compliant with the RFC but it tries to implement most styles of Authentication-Results header seen in the wild.

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

Alpine is a text-based mail and news client. Alpine includes several tools and applications:

1. alpine, the Alpine mailer

2. pico, the standalone text editor, GNU nano's predecessor

3. pilot, the standalone file system navigator

libESMTP is an SMTP client that manages posting (or submission of) electronic mail via a preconfigured MTA.

It may be used as part of a MUA, or other program that must be able to post electronic mail where mail functionality may not be that program's primary purpose.

libESMTP's high-level API shields developers from the complexity of SMTP. It transparently handles many SMTP extensions including authentication, TLS, and PIPELINING for performance. Even without a pipelining server, libESMTP offers much better performance than would be expected from a simple client.

Rspamd is an advanced spam filtering system that allows evaluation of messages by a number of rules including regular expressions, statistical analysis and custom services such as URL black lists. Each message is analysed by Rspamd and given a spam score.

Email::Simple provides simple parsing of RFC 2822 message format and headers.

This package provides a TNEF stream reader library and related tools to process winmail.dat files.

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

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.

Email::Address implements a regex-based RFC 2822 parser that locates email addresses in strings and returns a list of Email::Address objects found. It is recommended to use Email::Address::XS instead.

neatmail is a noninteractive mail client. It generates a listing of the messages in a mailbox in mbox format and executes a list of ex-like commands on it.