Δαφνη Ευτυχια Αρθουρος

Absolutely certain? No. Reasonably convinced? Yes. (I figured that if I was going to complain about a lack of even rudimentary header-checking, I'd better take a very close look at the headers on the bounce message as well, just in case. The thought that some of the bounce messages could themselves be forged had occurred to me.)

Worst case, I fell for a forgery but at least didn't send yet another copy of the payload in response. Best case, they change the behaviour of their filter. Expected case: my message gets completely ignored but I blew off a little steam.