It doesn't work on Saved Search (Virtual) Folders. I've created virtual folders which aggregate all inbox, sent, drafts, spam and trash folders from all my 13 IMAP accounts. It's very useful, since I can see eg. all sent messages in a single view. I hoped this extension would work on virtual folders, but it doesn't. Can something be done about it?这个评论是针对附加组件的一个早期版本的（1.3）。
I'm sorry it doesn't work for you...
Just to clarify, this plugin is just a simple wrapper to the execute the "Run Filters on Folders" from Tools menu.
If you manually go to Tools menu and click on the "Run Filters on Folders", does it work?
I have never used it for saved search folders, and maybe, just maybe this functionality does not work for virtual folders.