Espresso

Espresso is a powerful permissions-based email client designed to completely eliminate spam as you define it from your Inbox. Espressos unique email filtering system is based on common sense. Everyone knows from whom they want to receive email. Anyone else who sends you messages is sending you junk, otherwise known as spam. Espresso does not filter junk. It only looks for messages you want to receive based on simple, yet powerful rules. Using a number of options available, you decide how to handle messages from unknown senders.

In addition to controlling spam, Espresso offers the following features to control how you manage email: lightweight and portable email client, powerful junk mail filtering based on permissions, filter messages using regular expressions, ability to add notes to individual messages, hide private messages from prying eyes, automatically blind copy on all outgoing mail, easily flag important messages and supports POP3, IMAP4, HTTP protocols. Version 1.11.33 may include unspecified updates, enhancements, or bug fixes.