Note: these are intended for pre-release testing and are not recommended
for production use.
Download
You can get the Thunderbird 3.1.1 builds here:
http://ftp.mozilla.org/pub/mozilla.org/thunderbird/nightly/3.1.1-candidates/build2/
Update
If you have previously downloaded a beta version of Thunderbird 3 or
have manually set your copy to be using the "beta" release channel for
updates, you can update yourself to Thunderbird 3.1.1 by selecting "Help
> Check for Updates".
Feedback and Bugs
If you see any issues with these builds, please report them in
GetSatisfaction (http://getsatisfaction.com/mozilla_messaging/) or by
filing a bug in Bugzilla.
Getting Involved
If you wish to help further with testing Thunderbird, or other
Thunderbird activities, please see our getting involved page:
http://www.mozillamessaging.com/about/get-involved/
Thanks!