Version:           1.13.6 (using KDE 4.4.1) 
OS:                Linux

This is a request for enhancement. I sort incoming mail in to many folders. I can easily mark all mail as read within a single folder, but I would like to be able to click a button that would mark all my unread mail, in all my folders and sub-folders, as read. 

Reproducible: Didn't try

Steps to Reproduce:
Have to right click on each folder in the mail folder tree, then click on "Mark all messages read" - would like an option to mark all mail throughout all my folders as read with a single click. I have over 30 folders that get populated and it becomes very tedious sometimes to mark all mail as read. 



I read mail on multiple machines because of the nature of my work. Once I've gone through the morning mail on machine "A" (which may entail hundreds of messages since I participate in multiple lists), it would be nice to be able to open machines B, C, D, etc and click a button to mark all mail in all folders as having been read...