Betterbird is a fine-tuned version of Mozilla Thunderbird, Thunderbird on steroids, if you will. … Tesiwaju kikaBetterbird

Sylpheed is a simple, lightweight but featureful, and easy-to-use e-mail client. … Tesiwaju kikaSylpheed

Balsa is an e-mail client for GNOME, highly configurable and incorporating all the features you would expect in a robust mail client. … Tesiwaju kikaBalsa

Claws Mail is an email client (and news reader), based on GTK+, featuring

Quick response
Graceful, and sophisticated interface
Easy configuration, intuitive operation
Abundant features
Extensibility
Robustness and stability … Tesiwaju kikaClaws Mail