TabMail   
http://dlg.krakow.pl

TabMail for Windows (95/98/Me/NT/2000/XP) is mail user agent (MUA) for sending, receiving and managing your email messages. It's small and fast, conforms Internet Standards and supports Unicode characters. Some other properties: * Automatic attachments compression with zlib library * Warn when open (or save) dangerous attachments * Message filtering (input and output) using regexp TRE library * Spam filtering using SpamBayes message header additions * Simple view of compound messages * Message-thread can span many mailboxes * HTML messages view as plain text (see htmlp for more details). * Easy PGP message encryption/decryption * SMTP and POP3 authentication * Support for SSL/TLS connections * Scanning attachments for viruses * Multi-user and multi-account * Tracing for diagnosing TCP, POP3, SMTP or filter errors