MIME and Processing Feedback Loop Messages

Question

I'm trying to process Feedback Loop (FBL) messages to unsubscribe people that mark an email as spam (yes it's opt-in, and there is a one-click opt-out mechanism).

My first attempt is to use Advanced MIME Parser/Creator/Editor. However, FBL messages from major ISPs such as AOL and Yahoo are not correctly parsed. I posted that particular issue directly to the project's discussion forum.

My two-part question for the SO community:

• Is there another MIME processing library for .NET that I'm missing?
• Is there a good explanation of the MIME message format for non-SMTP experts out there? My Google searches turn up things that are either incomplete, or written assuming the reader is already very familiar with SMTP and email handling.

Answer 1

Check out Hunny Software. http://www.hunnysoft.com/ I've used their MIME libraries in the past and have had great experience with them.

Answer 2

Advanced MIME Parser/Creator/Editor never worked correctly for me. A commercial library is not an option for this task.

I ended up just properly decoding the MIME message (be sure to properly handle line breaks) and looking for relevant keywords. That worked fine for this particular problem.

Answer 3

My team has been using Rebex Secure Mail for .NET for two years and it is really solid. Our service (http://nutshellmail.com/) pulls down millions of POP3 and IMAP messages across all major ISPs on a daily basis. Rebex successfully parses the headers of all these messages. We also use Rebex for our outbound SMTP needs.

The full version of SecureMail is $350 (though for your purposes you could probably get away with the $250 POP3-only version). We have hit some obscure problems in the past (i.e. GoDaddy's POP3 servers not fully complying with RFC1939); Rebex support was extremely responsive and quickly provided us with a patch.

Rebex Secure Mail: http://www.rebex.net/secure-mail.net/