After the preparations described in an earlier post, we've shipped Betterbird 140.3.0esr-bb11 today. Fingers crossed that there will be no issues which would make a replacing the release necessary*). Please refer to the Release Notes for the full details.
Expert tip: You can always follow the Mozilla/Thunderbird ESR release schedule, which we mostly follow.
As of today, the 128 series has reached its end-of-life status. The 115 series hasn't been supported since February 2025, although some folks still use it as the last version that will run on Windows 7.
*): Update: there weren't. For the previous release 140.2.1, we did a "build2", not because the initial build had an issue, but to squeeze in another bugfix after the initial release.