Freeware from mozilla downloads
Thunderbird 1.5
Full-Featured Email Simple to use, powerful, and customizable, Thunderbird is a full-featured email application. Thunderbird supports IMAP and POP mail protocols, as well as HTML mail formatting. Easily import your existing email accounts and messages. Built-in RSS capabilities, powerful quick search, spell check as you type, global inbox, deleting attachments and advanced message filtering round out Thunderbird`s modern feature set. Junk Mail Filters Each email you receive passes through Thunderbird`s leading-edge junk mail filters. Each time you mark messages as spam, Thunderbird improves its filtering so you can spend more time reading the mail that matters. Thunderbird will also use your mail provider`s spam filters to keep junk mail out of your inbox. Anti-Phishing Protection Thunderbird protects you from increasingly common email scams
SeaMonkey 1.0
Web-browser, advanced e-mail and newsgroup client, IRC chat client, and HTML editing made simple -- all your Internet needs in one application. The SeaMonkey project is a community effort to deliver production-quality releases of code derived from the application formerly known as "Mozilla Application Suite". Whereas the main focus of the Mozilla Foundation is on Mozilla Firefox and Mozilla Thunderbird, our group of dedicated volunteers works to ensure that you can have "everything but the kitchen sink"