The classic email sending library for PHP
A faster, leaner email client and fork of Nylas Mail
Open source email service with a strong focus on security and privacy
High performance, self-hosted, newsletter and mailing list manager
Unofficial ProtonMail Desktop App
Lightweight Open Source webmail written in PHP and JavaScript
Anti-Spam SMTP Proxy Server implements multiple spam filters
Windows eml and mbox viewer.
SMTP email proxy and relay server
Powerful Open Source Email Marketing app with analytics & segmentation
Client daemon to move mail from POP and IMAP to your local computer
mailbox synchronizer
Fast Bayesian spam filter along lines suggested by Paul Graham
SOGo Zero-Effort-Groupware
Universal server
SaltOS, ERP, CRM, Business Management Suite, Josep Sanz Campderrós
C library for sending e-mail (with attachments) from C/C++
OpenXP 5 - a multi-protocol offline mail and news reader
Mailing List Manager - Web-based, Self-Hosted, Feature-Rich