How did you enable threading ?

If you press / and * do you see the threads expanding and collapsing?

It would help to have a screenshot, if possible.

If you need help to create a screenshot, please see How do I create a screenshot of my problem?

Once you've done this, attach the saved screenshot file to your forum post by clicking the Browse... button below the Post your reply box. This will help us to visualize the problem.

Thank you!

Hello Fabian, thanks for the reply!

I enabled threading through View > Sort By > Threaded

When I hit \ and * the threads do expand and collapse. I will try to provide a screenshot soon though it may be heavily redacted as this seems to only happen in threads to our external vendors.

Also it may be of interest that I can "repair" the threaded emails by moving them to another folder and then back to my inbox. (Which is why I don't have an example currently)

Thanks again!

-VJK

Threading is problematical at beast and plain painful at worst. Some mail providers web sites simply do not do threading, so the references header that is used is not included in the reply. That does not stop me using it though.

There are some settings you can change to hopefully make it work better for you. http://kb.mozillazine.org/Stop_threading_by_subject

Thanks Matt! I am hopeful about the mail.correct_threading setting as the issue only seems to happen with emails received from a different timezone, and it would also explain why the threading is fixed when moving it to another folder and then back to the inbox.

I haven't had any issues with threading since I toggled the mail.correct_threading setting, thanks Matt!