Postfix - Postfix is a mail transfer agent (MTA) that routes and delivers electronic mail.

Img.vision - Image hosting & video hosting for eCommerce sellers

mailcow - An open source mailserver suite.

BeeIMG - BeeIMG is a simple, fast, easy image sharing solution created to fill up your image sharing needs.

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.

ImageVenue - ImageVenue is a great online hosting service that allows uploading pictures for showing creative works with a simple-to-use technique.