Mutt

Still developed predecessor to Claws Mail, lightweight mail client

Old school email client (and news reader), based on GTK+

Free email application that's easy to set up and customize

Client/Server Open Source Network Backup for Windows, MacOS and Linux

Simple IMAP migration tool for copying mailboxes to other servers

Multi-protocol policy server (radiusd) that implements RADIUS, DHCP, BFD, and ARP and associated...