On an IMAP email server, when an item is marked for deletion, it is displayed in strike-through text in the header list. However, in reality that item is not actually Removed from the mail server. This is where the Purge command comes in handy.
- You can change the view of IMAP folders so that items marked for deletion do not appear. to do so, on the View > Current View >> Hide Messages Marked for Deletion.
- If emails are not purged, the marked-to-delete items will remain on server, and might cause exceeding the allotted disk space on your e-mail server.
Manually purge deleted items
To permanently delete the items marked for deletion, do the following:
Click a folder in your IMAP e-mail account.
On the Edit menu, point to Purge Deleted Messages.
Automatically purge the deleted items
You can configure Microsoft Outlook so that when you switch between folders, any items you have marked for deletion are purged from the IMAP mail server, automatically.
Click a folder in your IMAP e-mail account > Edit menu, point to Purge Deleted Messages > Purge Options (The Internet E-mail Settings opens) On the General tab, under Purge Options, select the Purge items when switching folders while online check box.