I have a custom application that was built to send opt-in newsletters and marketing emails. It does a pretty good job sending mail, but it doesn't respond at all to bounces or unsubscribe requests. It seems to me that rather than building that functionality myself I should use a mailing list manager such as LISTSERV.
However, I'm not sure if LISTSERV fits the bill. I need something that I can integrate with existing data and code.
For example, the newsletters are sent out to registered users on a couple of web sites. I can't figure out if there's a way to pull the addresses for a newsletter from an existing database. Also, I'd like people to be able to opt in and out using the same account administration interfaces they use now. I'd rather not expose users to the underlying mailing list management software.
Does LISTSERV have an API that would allow me to extend it to suit my needs? If not, is there another quality mailing list management tool that does?
LISTSERV does have a powerful (if baroque) programming interface; see http://www.lsoft.com/manuals/15.5/LISTSERV15.5_AdvancedTopicsManual.pdf.
mailman doesn't have an API per se, but it does have a complete set of command line tools, which makes it very scriptable.
And, of course, both mailman and majordomo come with all their source code (Python or Perl respectively) so it would be possible to customize either in any way you wanted. Or, if all you want is the bounce-processing, you could rip that part out of one of them.