If the message list is set to show messages in thread view and the messages are sorted by date, the sorting is done after the first message of the thread, thus making the new messages very hard to find if they are in an old thread. Reproducible: Always Steps to Reproduce: 1. Set View Aggregation to Standard mail list 2. Set sorting to Date/Time 3. Have a few mail threads 4. Receive new mail in those threads Actual Results: The new messages are very hard to locate, because the list is sorted by the date of the first message in the thread, not the last. Expected Results: The thread should be moved at the top of the list. The sorting should be done by the date of the last message in the thread. As an example of this functionality, you can try the same thing in Mozilla Thunderbird.
Bug Report Invalid. (or it was fixed) There is a sorting option that does this: View -> Message List -> Sorting -> By Date/Time of most recent in Subtree.