It always annoys me to see an old old mail as a new one in the IMAP folders. Even more it confuses me to see a new order confirmation from a seller when I never ordered something the last time - it takes some times a few momements to catch the fact it's an old mail and i've ordered nothing new by mistake. Well, as I saw this addon recently I reinstalled Thunderbird which never will fly now on a time travel and take something old forward to the presence. And more, the second caveat i cannot confirm. I deselect the 'date' column and all threads are sorted always by 'received' - after each restart too. And even if I keep 'date', the threads keeps my choice for 'received'.
Thank You for this essential addon.
This review is for a previous version of the add-on (1.0).