Elaborate on Courier-MTA further

README.md

@@ -153,6 +153,7 @@ Some [Groupware](#groupware) solutions also feature calendar/address book editin
 
 *MTA - Mail Transfer Agents (SMTP servers).*
 
+* [Courier MTA](http://www.courier-mta.org/) - Fast, scalable, enterprise mail/groupware server providing ESMTP, IMAP, POP3, webmail, mailing list, basic web-based calendaring and scheduling services. ([Source Code](http://www.courier-mta.org/repo.html) `GPLv3` `C`
 * [Exim](http://www.exim.org/) - Message transfer agent (MTA) developed at the University of Cambridge.
 * [Haraka](http://haraka.github.io/) - A high-performance, pluginable SMTP server written in JavaScript.
 * [MailCatcher](http://mailcatcher.me/) - Ruby gem that deploys a simply SMTP MTA gateway that accepts all mail and displays in web interface. Useful for debugging or development.
@@ -164,7 +165,6 @@ Some [Groupware](#groupware) solutions also feature calendar/address book editin
 
 *MDA - Mail Delivery Agents (IMAP/POP3 software).*
 
-* [Courier IMAP/POP3](http://www.courier-mta.org/imap/) - Fast, scalable, enterprise IMAP and POP3 server.
 * [Cyrus IMAP/POP3](http://cyrusimap.org/) - Intended to be run on sealed servers, where normal users are not permitted to log in.
 * [Dovecot](http://www.dovecot.org/) - IMAP and POP3 server written primarily with security in mind.