Sometimes, when a new POP3 message is moved out of the inbox folder to another folder by a filter and the Unread count in the folder list for that folder is 1, the new message isn't displayed in the message list. It's necessary to quit Kontact/Kmail and restart in order to see the message. It happens only rarely, every 10 days or something like that. It seems to have started in the last few months, some time during 4.10.
The same thing has happened with a message delivered directly from the local system to a local folder, without filtering. That is, the Unread count in the folder list for the folder was 1, but I could only read the message after quitting and restarting Kontact. I'll edit the bug title to remove "after filtering".
Also happened to me with IMAP and POP3 accounts. With and without filters. And it happens very often. I need to restart kmail about 20 times a day.
Forgot to mention: Kmail 4.10.4 and all other versions from 4.10. Kubuntu and Arch Linux.
*** This bug has been marked as a duplicate of bug 312460 ***
This is wrong. It is not the same bug. This is not a duplicate of bug 312460!! 312460 reffers to an incorrect number of unread emails to a folder caused by a filter. This bug reffers to an actual unread mail shown in the folders list, but not in the message list when the folder is selected. Please correct! (In reply to comment #4) > > > *** This bug has been marked as a duplicate of bug 312460 ***
My mistake. The duplicate is marked correctly. The initial description of the bug 312460 is misleading.