Mozilla Thunderbird 1.0 released on 6 December 2004

So I was two days late on the last one and eleven days late on this one, but here we go anyway...

Thunderbird is the stand-alone email client companion to the Firefox stand-alone web browser. Thunderbird was originally known by the project name Minatour, and has since evolved into an email client that may one day overturn Outlook Express as the most-used stand-alone email client.

Since the roadmap for Thunderbird hasn't been updated since 3 November 2004, I was unable to determine when upcoming major released are planned.