...nor a mail server with orange fur?
Orange.fr has a misconfigured mail sever! (Points accusing finger at Froggy sysadmin.)
I woke, this fine furry Monday morning, to an inbox full of bounce messages, in French, almost all from orange.fr (the other two were vacation autoresponses, which are inherently handled differently from bounces).
The bounced messages hadn't originated on my server. They were, presumably, the usual spam-with-fake-return-address (I don't go opening .eml attachments just to see what someone's been circulating).
Uh, guys? If you reject an incoming message, the civilized way to handle it is to make the determination before accepting it for delivery, and just reject it during the data phase. Not to accept it for delivery, and then e-mail a bounce message to to poor slob whose address appears in the from: field.
The 90s called. They want their naïveté back.