IMAP

Internet Message Access Protocol.

Internet Message Access Protocol, Internet Message Access Protocol

IMAP FileSystem

http://www.lumisoft.ee/lsWWW/ENG/Products/Mail_Server/mail_index_eng.aspx?type=info

MailSystem is a suite of .NET components that provide users with an extensive set of email tools. MailSystem provides full support for SMTP, POP3, IMAP4, NNTP, MIME, S/MIME, OpenPGP, DNS, vCard, vCalendar, Anti-Spam (Bayesian , RBL, DomainKeys), Queueing, Mail Merge and WhoIs

http://mailsystem.codeplex.com/

A C# implementation of IMAP.

http://imapnet.codeplex.com/