Thanks for the test PM. I got the same email to my signup email account saying that it can't be delivered because I've reached my quota on PMs. I tried all the same stuff and I could post the same screenshots as I did previously.
I'll give it a couple of days and if Texas1911 can't get it fixed, I'll try to delete the 100 messages that the system says I have stored in empty folders and that I can't download because I have no messages. (Yes, I found that as confusing to write as it was to read.)
I'll rebuild the indexes and see what happens.
Also, as a short term fix, I upped the PM storage to 200.