OK. That didn't work. I noticed that after I put it in the trash, it replicated itself immediately in Finder. So, if it is corrupted, it just replicated the same corrupt file, I guess. I decided to quit mail and then go to Finder and do it all over again but, again, I got the "the folder can't be found" message. Cripes!
You could trash it and then drag it from Trash to the desktop. Of course, you could leave it in Trash for later retrieval, but that's risky; you might inadvertently empty Trash.
