--On Montag, August 15, 2005 01:40:25 +0200 Frank Ellermann
If an RFC defines X = Y, then it cannot say "<X> MUST be <Y>",
it's a definition and no requirement. So the MAIL FROM is the
Return-Path, it's not any "report-trouble-elsewhere-address".
What is the distinction between "return mails to X" (as opposed to "send
replies to X") and "report errros to X"? You only send mail to the return
address when you have something to report about its delivery status. In all
other cases you should use the data from the message itself not from the
Did you mean that the return-address may not be identical to the address of
the original sender?