Here is a very very simple implementation of an SMTP Server for Windows Azure. This sample saves E-mails to storage.
Remember: even when this seems relative simple, you must take into account the following:
- Parsing MIME is a more complicated task (specially with non-compliant MIME clients). I’ve found some alternatives here, here and here (there are several others).
- One of the most important components in a email server is SPAM filtering (you won’t get this feature implemented such as easy as you could imagine)