Well, to shorten a long story,
I had a debacle of an experience last year,
trying to use a little flip phone as a mobile device.
It's cancelled now, but I did end up with a mobile phone number.

So, out of curiosity, I pulled up the US Mail online form
for a forwarding address,
and submitted the cancelled mobile phone number.
And guess what -- it went through.
So now my mail will be forwarded as before, for another six months.

The misadventures I get into ...