Version: (using KDE 3.5.9) OS: Linux Installed from: Ubuntu Packages I have sent a message to two people. It got stored in my Sent folder. Then one of them replied, and we had a small conversation. My replies to his replies were stored in Inbox. That was all as expected, and the conversation was threaded properly. Then the other one replied, and his message was threaded as though it were a reply to the other person’s reply to me, while I expected it to be on the folder’s top level. Alpine shows the messages this way: + A 645 9:33 Person 1 (2K) . Re: Subject 646 9:43 To: Person 1 (5K) . \-Re: Subject + A 647 10:01 Person 1 (3K) . \-Re[2]: Subject 648 10:39 To: Person 1 (7K) . \-Re: Subject + 649 15:17 Person 1 (6K) \-Subject + 650 17:22 Person 2 (74K) Re: Subject Mutt: 645 r + Aug 29 Person 1 (2.0K) ┬─>Re: Subject 646 sF Aug 29 To Person 1 (4.2K) │ └─> 647 r + Aug 29 Person 1 (3.0K) │ └─> 648 sF Aug 29 To Person 1 (6.3K) │ └─> 649 + Aug 29 Person 1 (5.4K) │ └─> 650 + Aug 29 Person 2 ( 72K) └─>Re: Subject But KMail thought message 650 was a reply to 645, while both are replies to a message that is not present in my Inbox. Turning “Thread also by subject” off helps. Unlike #81581, all messages have proper In-Reply-To headers and thus threading by subject should not be active.
I can confirm that threading has issues. In my case 650 is shown as reply to 647. I have kmail 1.11.2.
Thank you for taking the time to file a bug report. KMail2 was released in 2011, and the entire code base went through significant changes. We are currently in the process of porting to Qt5 and KF5. It is unlikely that these bugs are still valid in KMail2. We welcome you to try out KMail 2 with the KDE 4.14 release and give your feedback.