Several years ago I needed an MTA to run on an old MacOS X box that was running the Chaos In Motion web site, as well as the PandaWave web site. So I rolled my own. Didn’t need anything complicated; just something that could be scripted via XML and was running maybe a half-dozen different incoming e-mail locations.
So I rolled my own. I first rolled a library which could handle the SMTP and POP3 protocols, then an implementation that extended the library to store incoming and outgoing messages in various directory locations on the server box.
Years later, and I don’t have the time to productize this. Further, most MTAs seem to be moving towards being free and open source–so I may as well upload it under the BSD license in case someone out there finds it useful.
Which I did.
The library that implements the POP3 and SMTP protocol and parses incoming requests was uploaded here (MailServer), and the server code which implements the MTA database back end is uploaded here (CIMMail). I’ve also included the necessary MacOS X scripts to start up a Java server in the background, though it should be fairly simple to create a Windows Service and a Linux script which does the same thing on those platforms.