Why "Delete" Does Not Mean Immediate Deletion
One of the quirks of IMAP is that messages are neither deleted immediately when you press Del nor moved to a Trash folder but "marked for deletion" until you purge the folder.
In the default view used by Outlook for IMAP accounts, this has the consequence that "deleted" messages are displayed grayed out and with a strike-through line. But they are still visible. Now, either you purge your inbox constantly, or you deal with the irritation of lots of messages that are, in a way, undead — or you tell Outlook to hide these messages.
Hide Strikethrough Messages Marked for Deletion in Outlook
To hide messages already marked for deletion in Outlook:
- Select View | Current View | Hide Messages Marked for Deletion from the menu.
- In Outlook 2003, select View | Arrange By | Current View | Hide Messages Marked for Deletion.
- Select View | Reading Pane | <desired setting> to re-enable the preview pane.