Mstone is a mail performance measurement system. It can simultaneously test SMTP, POP, IMAP, and some HTML based systems. It measures transaction latency in multiple stages, and graphs the combined results from multiple clients.
A series of projects used for Flagrun Networks (http://www.flagrun.net) this network is dedicated to hosting; open source projects, development websites, gaming mods, community sites. these are the tools used on flagrun, completely open source to the pub