Comment 32 for bug 1899485

I went ahead and did a fresh install of Linux Mint 17.3 Cinnamon 64-bit, which installed Thunderbird 52.2.1 (64-bit). I then grabbed davmail-linux-x86_64-4.8.0-2479.tgz and ran it with all out-of-the-box settings. I then set up a new account in TB, pointing at localhost to use davmail, and successfully connected to my Office 365 account. I was able to reply to messages in my inbox successfully, without issue.

Of course, since this was a fresh install of Mint, it was a fresh install of TB, as well. Not sure if there's a way I can (easily) install an older version of TB, then let it update itself to the latest version. Will try that next, but just wanted to update everyone that I still haven't been able to reproduce this, so far.