Auto delete in webmail

[Santaclaus]

I am using Plesk 7.5.6 with mail enable professional2.0

In Plesk webmail , when a customer is deleting mails , it goes to deleted folder and stays there till manually deleted.

How do I set webmail to either:

1) Directly delete mails upon delete from inbox

OR

2) Delete mails in deleted folders every 24 hours or so.

Thanks for all help provided.