Version: 1.12.2 (using KDE 4.3.2) OS: Linux Installed from: Ubuntu Packages My inbox has about 28,000 messages in it, and when I enter that folder, kmail 1.12.2 takes about 25 seconds to process, thread, and group all those messages. For this same folder (it's on an IMAP server), kmail 1.9.10 takes about 3 seconds. kmail 1.12.2 is only slow if I use "standard mailing list" aggregation, which seems to look the same as the way I have kmail 1.9.10 configured.
Does anybody pay attention to these? I fully expect that this is a configuration error on my part, but I have no idea how to find it, and this makes kmail unusable for me.
This issue still exists in Kubuntu 10.04 LTS, Kmail 1.13.2, KDE 4.4.2. This IMAP inbox folder now has 31,000 messages in it. Entering the folder using "Activity by date, flat" organization takes about 1 second. Using "standard mailing list" aggregation takes about 18 seconds. On Kubuntu 8.04.4 LTS, Kmail 1.9.10, KDE 3.5.10, entering the folder takes about 2 seconds, using message list settings equivalent to "standard mailing list."
I finally figured out that the problem is not related to "standard mailing list" aggregation; rather, it's related to "always expand threads."
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.