Mozilla's Thunderbird mail client is a redesign of the Mozilla mail component. Its goal is to produce a cross-platform, standalone mail application using XUL. It is modeled after the Mozilla Firebird rewrite of the Mozilla browser. The intended customer is someone who uses Mozilla Firebird (or another non-Mozilla browser) as his or her primary browser and who wants a mail client based on Mozilla that plays nice with that browser. Some of the new features in version 0.8 are a global inbox, comprehensive data migration, RSS integration, improved privacy controls, and improved quick search. Thunderbird now supports a user interface for creating multiple identities for each e-mail account.
This software may work well enough to be relied upon as your primary messaging client, as it's based on the stable Mozilla 1.6 architecture. However, Mozilla Thunderbird is still a preview release, and therefore several features may not be complete.
Note: Do not install Mozilla Thunderbird into a directory containing program files from a previous version. Overwriting files from a previous release will cause problems. To re-use the directory of a previous install, the directory must be deleted and recreated, emptied, moved, or renamed. You should not file bugs in Bugzilla if you choose to ignore this step. If you used a prior version of Thunderbird and installed themes or extensions, you need to do the following or Thunderbird will not run properly: Find your profile directory. There should be a subdirectory called Chrome. Remove everything in Chrome (this will not affect your mail data or Preferences). You will then need to re-install the 0.8-compatible version of any themes or extensions you want.
Beta or prerelease software is not intended for inexperienced users, as the software may contain bugs or may potentially damage your system. We strongly recommend users exercise caution and save all mission-critical data before installing or using this software.