Using Gecko/2008080600 (SM trunk nightly) Incoming emails that do not reference any other mails, and hence should be shown as starting new threads instead get buried down inside other threads. This is seen in both POP3 and IMAP accounts. Rebuilding the Summary file (bonking the "Rebuild Summary File" button in the folder's properties dialog) fixes this (makes the new thread appear to be a separate thread again. Was not seen with 2008080100, but is being seen A LOT today. I'm having to rebuild the summary file of most folders that I read to see the threads threaded properly.

Marking as qawanted since it would be interesting to pin down the regression range more tightly, ideally to the point of associating it with a checkin. Marking as a blocker since it's a regression, and an annoying one at that.

Nelson, are the new messages buried in the thread because they have the same subject? We did change the threading rules IIRC. (changing the flag to correspond to what dmose said he did =)

David, the problem is seen with new messages with new (different) subjects.

Nelson, still see this?

Is anyone seeing this anymore? There have been a fair number of fixes, and no more reports that I know of about issues like this. My inclination is to take it off the blocking list unless someone is still seeing it.

(In reply to comment #5) > Is anyone seeing this anymore? assuming not. I haven't seen this in a long time => WFM but please reopen if you can reproduce with current trunk or recent beta.