I am having issues with an account I administer and spam. The email addresses (many) are filling up with spam quickly and I am having to go in and manually clear the spam box for them to begin to receive emails again.

They are using Outlook Express/Thunderbird setup with pop access.

Is there some way to automate this so that the box is cleared every week or when it reaches its limit?

If there are questions I have left unanswered please let me know.