Calypso is an excellent, well-designed e-mail package.
Calypso's user interface offers a customizable three-window view that includes a MessagePreview panel which allows you to view your messages without opening them. Calypso comes with a spell-checker and supports drag and drop e-mail management. A "blind" copy and send option lets you automatically send recipients personalized e-mail. A "redirect" option lets you forward mail to others without changing the reply-to address, making it easier for the person receiving the mail to reply to the sender.
Other features include: the option to preview your mail before downloading it from the server, support for multiple accounts, highlighted URLs, mailbox backup, advanced filtering, Eudora address book support, spam control, configurable word wrap, unlimited signatures, the ability to automatically add addresses to the address book, the ability to import e-mail addresses from other programs, bulk mail, mail templates, and support for decoding MIME, BinHex and UUEncoded files.
This latest release offers a number of enhancements -- complete details can be found here.
