Nikilet 0 Newbie Poster

I have one email that I can't delete from my Windows Mail Inbox. I did delete a bunch of emails from the Inbox, the Delete and Sent folders but there is just this one that won't go. It is a short reply to a question I sent to my bank. When I try to delete it I get a pop up that says "an error has occured." There is no number or anything.

I am using Vista Home Premium.