On Mon, Aug 15, 2005 at 07:25:58AM +0200, Ralf Doeblitz wrote:
Did you mean that the return-address may not be identical to the address of
the original sender?
Sure, that is the case when there is an intermediate destination.
See RFC821, "2. THE SMTP MODEL", paragraph 2:
"Once the transmission channel is established, the SMTP-sender
sends a MAIL command indicating the sender of the mail."
Note that it not says "... indicating the originator of the mail."
In "3.2 FORWARDING" error 551:
"The receiver refuses to accept mail
for this user, and the sender must either redirect the mail
according to the information provided or return an error
response to the originating user."
Again, 'sender' and 'originating user' are different.