Using KMail, I see the number of unread messages EQUAL to number of all messages in the folder! Reproducible: Always
? Screenshot please
Created attachment 80917 [details] Image describing the bug
(In reply to comment #1) > ? > Screenshot please I've attached the screen shot. As you can see, the unread messages are 'red' while the read ones are 'black'. In the folder pane, you can see total unread and total messages have the same value.
Donwgrading qt to 4.8.4 instead of 4.8.5 fixes the bug (I'm using postgres with Akonadi). See here http://cgbdx.wordpress.com/2013/07/17/note-for-the-akonadi-pgsql-users/