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
Unofficial ProtonMail Desktop App
Lightweight Open Source webmail written in PHP and JavaScript
High performance, self-hosted, newsletter and mailing list manager
Anti-Spam SMTP Proxy Server implements multiple spam filters
Windows eml and mbox viewer.
SMTP email proxy and relay server
Sync Outlook with Google, SOGo or any other CalDAV / CardDAV server
Powerful Open Source Email Marketing app with analytics & segmentation
Client daemon to move mail from POP and IMAP to your local computer
Sync Outlook contacts and calendars with Google
mailbox synchronizer
Fast Bayesian spam filter along lines suggested by Paul Graham
SOGo Zero-Effort-Groupware
Universal server