Offers integrated e-mail, address book, calendar, and newsgroup reader. Includes feature description, documentation, upgrade support, and trial download.

A fully featured mail application running on Linux (or FreeBSD, OpenBSD, etc) and Apple Mac OS X. It uses the GNUstep development framework or Apple Cocoa.

Barebones Software's mail client with wide variety of features for beginning and power users. For OSX and 9.

Offers multi-lingual e-mail with right-to-left or left-to-right typing, spam filtering, HTML mail, SMTP authentication, auto-forwarding, and some AppleScript support. OS X and OS 9. Includes feature descriptions, FAQs, trial download, and upgrade option.

Offers built-in spam filter and integration with SpamSieve, POP and IMAP support, customizable toolbars, AppleScript support, multiple filter rules, and SMTP authentication. OS X only. Includes feature descriptions, FAQ, testimonials, trial download, ...

A Macintosh application that adds single-click encryption to your Eudora email.

Offers POP and IMAP support, SMTP authentication, filter rules, multiple accounts, and spam filter. For OS X and OS 9, as well as Windows XP. Includes documentation, support forums, and trial download.

Offers integration with older versions of AOL, Applelink, and Compuserve. OS 7 and 8 only; no longer maintained or supported. Includes free download.

Offers drag-send feature, global window, auto-send-attachment directory, and external word processor compatibility. OS X and OS 8.5 and higher. Includes feature description, support forum, screenshots, and trial download.

Offers e-mail access via any Java enabled browser. Includes feature description, online demo, and trial download.