Purge IMAP items marked for deletion in Outlook 2003
When you mark an item on an IMAP e-mail server for deletion, it is displayed in strikethrough text in the header list. To permanently delete the items marked for deletion, do the following:
On the Edit menu, click Purge Deleted Messages.
Please note: If you do not purge deleted items periodically, you might reach and exceed the allotted disk space on your e-mail server. If you exceed your allotted disk space, you might not receive any new messages.