The systray icon of kmail doesn't show the custom icon for new mails but the default. If there are no unread mails, the custom icon is displayed properly. In ~/.kde/share/apps/desktoptheme/[THEME]/icons/ is a kmail.svg which contains one icon for read an one for unread mails. This worked fine untill the release upgrade from Kubuntu 13.10 to 14.04. Reproducible: Always Steps to Reproduce: 1. Open Kmail an configure systray icon to show up permanently 2. Wait for new mails 3. Mark mail as read Tested with this svg: https://dl.dropboxusercontent.com/u/704653/kmail.svg The icons in the svg should be named correct.
https://dl.dropboxusercontent.com/u/704653/mail.svg
With default theme it works. So kmail works. Perhaps it's a problem in your theme.
This bug has only been reported for versions before 4.14, which have been unsupported for at least two years now. Can anyone tell if this bug still present? If noone confirms this bug for a Framework-based version of kmail2 (version 5.0 or later, as part of KDE Applications 15.12 or later), it gets closed in about three months.
Just as announced in my last comment, I close this bug. If you encounter it again in a recent version (at least 5.0 aka 15.08), please open a new one unless it already exists. Thank you for all your input.