Mozilla Thunderbird is a fast and very functional GUI mail client. It features excellent online/offline mail reading, IMAP, POP and local mail transfer protocols, security with X.509 and GPG key management, and a plethora of extensions.
Thunderbird follows in the tradition of Mozilla Firefox. It is a focused, lightweight mail client with very good extensibility through the Mozilla extension mechanism.
Thunderbird is widely localised and available in many languages.
All packages Packages in Distributions
thunderbird-locales source package in Lucid
Version 1:3.1.7ubuntu0.10.04.1 uploaded on 2011-01-20
thunderbird source package in Xenial
Version 1:38.4.0+build3-0ubuntu1 uploaded on 2015-11-25
thunderbird source package in Wily
Version 1:38.3.0+build1-0ubuntu2 uploaded on 2015-10-14
thunderbird source package in Vivid
Version 1:38.3.0+build1-0ubuntu0.15.04.1 uploaded on 2015-09-30
thunderbird source package in Utopic
Version 1:31.8.0+build1-0ubuntu0.14.10.1 uploaded on 2015-07-15