Can't Delete Messages

[MichelleP]

When I try to delete older messages (1-2 yrs old) I received the following
error message: "The Messaging interface has returned an unknown error. If
problem persists, restart Outlook." I've tried the Outlook Repair tool - no
avail. How can I get rid of these messages? --Thank you.

 

[Al Martino]

Try using Shift-Delete