Proper settings for K9 Mail for deleting trash

[aaf709]

I've been using K-9 Mail for my Cox account. It works fine, except for one thing. I never seem to get rid of emails I've deleted. Oh, they're gone from the server, but when I go to delete from the trash, it may pop up again.

I use Select All, but it only take care of a bit. And when it won't load any more and I go back later, they're still there. Some are months old.

Is there a setting to prevent that?

Thanks!