Full SMTP/Mail server Appliance in 5 minutes
File system benchmark
an 'auto-reply' bot for your mail server
CheckeredFlag is a super simple mail server.
An unofficial web console to administer Apache James 3 server
To synch and encrypt all sorts of data across different sources
MailSmsGateway is a simple interface between mailing and sms services.
Ciphermail email encryption gateway (S/MIME, OpenPGP, PDF encryption)
javascript to convert thunderbird/seamonkey filters to sieve rules
Webkosa is the open source edition of Webcrossing.
AV/content filter for Qmail
A lite version of mailinator for developer use