At it's core Lamson is just a really sweet wrapper around smtpd (http://docs.python.org/library/smtpd.html) using asyncore for asynchronous socket IO.

When a mail is received you can optionally process it and when done processing you can drop it on the floor (e.g. you're done with it) or you can send it to a 'relay' which means a IMAP or POP server (or really anything) if you so choose.

I would generally say that yes, lamson is much more focused on receiving email via SMTP and doing [smart] processing on it.

I would imagine that its parsing functionality could be a boon to someone wanting to do something higher level with IMAP. Thanks for the response.