That is intentional. Therefore a "Won't Fix" status is appropriate here.
https://blog.mozilla.org/security/2016/10/24/distrusting-new-wosign-and- startcom-certificates/ -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1691333 Title: upgrade to 52.1.1 breaks smtp starttls on 16.04 and 17.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/thunderbird/+bug/1691333/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs