The Magama is an open-source mail-server application daemon for SMTP, POP, IMAP, HTTP, and MOLETN.
It offers additional support for DMTP and DMAP.
Magama features webmail with JSON-RPC interface, which requires some work to install.
The software package is available for Linux, especially CentOS 6 distros. Also, it can be installed using vagrant on other Linux systems.
It is written in the C programming language.
It requires MySQL server, Memcached, Perl, and GCC compiler.