Created attachment 66715 [details] Screenshots Version: 4.7 (using KDE 4.7.3) OS: Linux Threading by subject seems to create erroneous threads in some cases, when many mails should be grouped under one parent mail. Reproducible: Always Steps to Reproduce: Create an email with the subject "Test". Create several emails, each with the subject "Re: Test" to imitate responses by MS Outlook. Actual Results: Of the "Re"-Mails, only some of them are placed on the correct level and the remainder is incorrectly placed to a third or even fourth level (see the second screenshot). Expected Results: All mails should be grouped at the same level under the parent mail. Also, from a certain complexity on, the threading seems to take place only after a restart, see the first screenshot (before restart).
I fixed a bug in 4.8 about threading. It's when Messages has not "In-Reply-To". Could you update your package ? or look at if there is a "in-reply-to" header ? if not I fixed it
Do you have still bug in 4.8RC2 ?