Supported protocols:
* POP3 / APOP
* IMAP4rev1
* SMTP / SMTP AUTH
* NNTP (News)
* SSL / TLSv1 (POP3, SMTP, IMAP4rev1, NNTP)
Features:
* multiple accounts
* thread display
* News reader
* printing
* address book
* template
* powerful filtering
* powerful search
* customization of toolbar
* mark / color label
and much more
Screenshot
Downloads
http://sylpheed.sraoss.jp/