TabMail for Windows is a mail user agent (MUA) for sending, receiving and managing your email messages. It's small and fast, conforms to Internet Standards and supports Unicode characters. Some other properties:
Simple view of compound messages.
Message-thread can span many mailboxes.
Warn when open (or save) dangerous attachments.
Easy PGP message encryption/decryption.
Automatic attachments compression.
SMTP and POP3 authentication.
Multi-user and multi-account.
||Free to try