For someone looking for a workaround, then the 100% CPU usage could apparently also be a result of TB reopening/reindexing databases too often. According to these links:
https://bugzilla.mozilla.org/show_bug.cgi?id=794401 http://rainbow.chard.org/2013/02/19/thunderbird-high-cpu/ it appears that "Technically ... [Thunderbird] check open DBs every minute, and if they have been open more than 3 seconds and there are no other references to them, they are closed. The '3 seconds' has now been changed to the original intent of 5 minutes." On my system, mail.db_idle.limit was set to 300000, which might have been the intended value... But I've increased it to 30000000 as others have suggested, which seems to help -- I have many really really large IMAP folders, so indexing is a slow process that can last minutes. Whether it has negative impacts elsewhere remains to be seen. But it is an easy tweak and fast to test -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/927515 Title: Thunderbird stuck at 100% CPU To manage notifications about this bug go to: https://bugs.launchpad.net/thunderbird/+bug/927515/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs