Anti-Spam SMTP Proxy Server implements multiple spam filters
The Free & Popular FLARUM Web Software in a Complete Virtual Machine
Booking/reservation of meeting rooms/equipment with e-mail invitations
Full SMTP/Mail server Appliance in 5 minutes
Wrappers around msmtp for use as queueing MTA with extra features
Open-Source Centos7 project to offer rapid communication apps.
A simple native java network library
Quick & dirty RSS-to-email tool