Email Inspire - Discover the best of email design and marketing — Browse email newsletters from top brands.
Postfix - Postfix is a mail transfer agent (MTA) that routes and delivers electronic mail.
EmailWay - Collection of the most insightful and informative email newsletters from across a wide spectrum of industries and interests
mailcow - An open source mailserver suite.
WhoSentWhat - We bring email newsletters from inbox to web
Mail-in-a-box - Mail-in-a-Box provides webmail and an IMAP/SMTP server for use with mobile devices and desktop mail software and also includes contacts and calendar synchronization.