We've shipped Betterbird 140.6.0esr-bb15 today. Please refer to the Release Notes for full details.
Update 8th December 2025: We had to replace the entire release with "build2" since advancing the Thunderbird "fix" for an IMAP bug introduced random crashes. On closer inspection, that code change is likely to have undesired effects, including crashes.
We've addressed issues reported by users in the last four weeks and implemented some new features.
First and foremost, to fund the project, when launching this version for the first time, it will open the end-of-year donation drive page in your browser. Unlike Thunderbird, which is constantly nagging, we're asking for donations this way only once a year in December.
A user who is migrating from Postbox motivated some improvements to the search functionality, see this post for details.
Some of the fixed bugs that were related to searching, for example we rectified and issue that prevented encrypted S/MIME messages to be indexed; a feature introduced in Betterbird 115.
Miscellaneous fixes include missing localisations, where the program talked about Thunderbird instead of Betterbird, and a fix for the much-dreaded "phantom menus" mentioned here. Users of "attachments on top" in the compose window can now reduce the height of the addressing header when many files are attached.