Official site. Open source cross-platform email and Usenet client based on Mozilla code. Features intelligent spam filters, built-in RSS reader, and quick search.

Themes are skins that allow you to change the look and feel of the browser and personalize it.

The official community marketing site for Thunderbird. Buttons and banners, affiliate program and forums.

Project to provide the functionality of the Sunbird calendar application as a thunderbird extension. Includes download and FAQs.

In depth history and information

Goal is to produce a cross platform stand alone mail application using the XUL user interface language.

Messages about bugs, features, builds, and the program in general.

A security extension which allows the use of authentication and encryption features provided by GnuPG.

Detailed installation guides and tutorials for Thunderbird

Full featured version for portable devices such as USB drives