Description: From the publisher's website:
Sylpheed is a simple, lightweight but featureful, and easy-to-use e-mail client.
Sylpheed provides intuitive user-interface. Sylpheed is also designed for keyboard-oriented operation, so Sylpheed can be widely used from beginners to power users.
Sylpheed runs on many systems such as Windows, Linux, BSD, Mac OS X and other Unix-like systems.
Sylpheed uses GTK+ GUI toolkit. The newest version of Sylpheed works with GTK+ 2.4 or later (2.6 or later is recommended).
Sylpheed has the following features. Read more...
Download Sylpheed Portable 3.5.1 Dev Test 1 (8.06MB download / 39.4MB installed)
See all release notes at the SourceForge project page
This has now been officially released: https://portableapps.com/apps/internet/sylpheed-portable