Tony Finch wrote:
I can see some comments about source routes which have been
deprecated since before RFC 1123 in 1989, but this is
unrelated to forwarding.
It is related. With source routes all forwarders were very
interested that their effort didn't result in bounces, because
they would be a part of the reverse path.
If senders don't want their email forwarded then they
shouldn't send email to anyone who will forward it.
Amen, 551 is beautiful, even in its SPF-FAIL "emulation", bye