MailKit is an Open Source cross-platform .NET mail-client library that is based on MimeKit and optimized for mobile devices.
Features include:
* SASL Authentication via DIGEST-MD5, CRAM-MD5, LOGIN, PLAIN, and XOAUTH2.
* A fully-cancellable SmtpClient with support for STARTTLS, 8BITMIME, BINARYMIME and PIPELINING
* A fully-cancellable Pop3Client with support for STLS, UIDL, and APOP.
* A fully-cancellable ImapClient with support for LITERAL+, NAMESPACE, CHILDREN, LOGINDISABLED, STARTTLS, MULTIAPPEND, UNSELECT, UIDPLUS, CONDSTORE, ESEARCH, SASL-IR, COMPRESS, ENABLE, QRESYNC, SORT, THREAD, ESORT, SPECIAL-USE, MOVE, XLIST, and X-GM-EXT1.
* Client-side sorting and threading of messages (the Ordinal Subject and the Jamie Zawinski threading algorithms are supported).
* S/MIME and PGP support via MimeKit