[Dovecot] Deleting deleted eMails

Hello 2gether,

I am using Dovecot 1.0.rc15 together with Outlook (I apologize) via IMAPS. Now I discovered, that all the old eMails, I marked for deleting, are still there, even the veeery old ones. Dovecot is marking the eMails (I am using maildir configuration) files with an "ST" extension. Is there any switch to turn on garbage collection and maybe a screw to tune the duration until deletion?

Thanks for your help!

Michael Weisgerber