Claws Mail is an email client aiming at being fast, easy-to-use and powerful. It is mostly desktop-independent, but tries to integrate with your desktop as best as possible. The Claws Mail developers try hard to keep it lightweight, so that it should be usable on low-end computers without much memory or CPU power.
Claws Mail sports almost everything a perfect email client needs. Mail retrieval over POP3, IMAP4, local mbox, over SSL; support for various authentication schemes. It has multiple accounts and mailboxes, powerful filtering and search functionality, import/export capabilities using a number of formats, support for GnuPG (digital signatures and encryption). It supports plugins, customisable toolbars, spell checking, a number of guards to prevent any data loss, per-folder preferences, and much more. A list of features can be found here.
Formerly known as Sylpheed-Claws, it started in April 2001 as the development version of Sylpheed, where new features could be tested and debugged, but evolved enough to now be a completely separate program. It forked completely from Sylpheed in August 2005.
Download: Claws Mail (64-bit) | 33.2 MB (Open Source)
Download: Claws Mail (32-bit) | 26.2 MB
Links: Claws Mail Home Page | Other Operating Systems | Themes | Plugins