Koma-Mail
Koma-Mail is a simple, portable email client, that can be run standalone from a USB drive. It allows you to send and receive email from your POP3/IMAP account. The program supports SSL and APOP and contains options to block scripts, ActiveX and HTML content for increased security. It also includes a basic spam filter option and can be used with multiple accounts and multiple users. Koma-Mail can import/export email messages and contacts, maintains an encrypted database and even includes a simple RSS feed reader.