I have proof that I sent it, so @wjjhoge had best indicate he received my answer to his irrelevant interrogatory.
— The Fat Man (@FatManPodcast) January 12, 2017
I sent a letter. I have proof that I sent it – it’s in this mailbox (or at least one that looks an awful lot like it):
So I DEMAND that to be informed that it was received.
By 5:00 PM today. Or I shall be angry.