I posted a question yesterday asking for help re emails being duplicated in the Inbox after moving them in Kmail.
No response.
Now I can't empty the Trash in Kmail! The option is greyed out in the right click menu and in the menu drop down under Folder on the toolbar.
I've had enough.
I'm going back to Thunderbird.
Kmail/Kontact used to be great, now it's just a collection of bugs that no one seems interested in doing anything about.

I would recommend referring to the thread in this same forum concerning Trash emptying problems.

Also, please mention what version of Kontact/KMail you are using.