For more than a year already, I've been using Peter Huber's POP3 Email Client for .NET 2.0. It has been working fine for me until recently when I tried automating some more processes. I found out that the old (2006) code does not handle different types of MIME attachments properly. Searching some more at Google, I found out Peter Huber had another C# POP3 class that handles MIME. I tried it out but found it just as complicated to use and poorly documented. And it still could not properly read 1 specific email format that I was receiving from a supplier.
I tried the OpenPop.Net project and it solved all my problems! Very simple and intuitive to use. Requires very little effort to read the MIME attachments. It handles all the transcoding behind-the-scenes beautifully. No need to know about Base64, QuotedPrintable, etc. It just works. I'm now migrating my old code based on the Pop3MailClient.cs to OpenPop.Net!