Why not have The Bat! do that automatically? I have one account that is set to be checked for new mail every 3 days (that's 4320 minutes), and whenever there is new mail, The Bat! will automatically bring up the Message Dispatcher so I can delete all the unwanted emails right at the server. Of course, you can also do this (using a higher checking frequency) with a more frequently used account.
Now, to launch the Message Dispatcher automatically in The Bat!:
- Go to the desired account in The Bat!.
- Select Account | Properties... from the menu.
- Go to the Mail management category.
- Make sure Invoke automatically at each mail check is selected under Mail Dispatcher.
- Click OK.

