Re: Forwarding problem with aliases

On 04.09.2024 um 14:09 Uhr Knute Johnson wrote:

I've got a sendmail server running that needs to forward a couple of
addresses to other destinations.  I've set these up in aliases.  Most
of these work but one recipient has an earthlink account and it
rejects the forwarded message if the sender is not local to the
sendmail server. The error message in the returned mail says "The
sender's address is rejected for policy reasons."  Kind of cryptic.
The end user whitelisted the server's domain but I don't think that
is where the issue is.  I think it is because the sender could be
from anywhere and that doesn't match the domain of our sendmail
server.  But that is just a guess.  If I send mail from an account on
the server to the one of the forwarding aliases, it forwards to the
earthlink account just fine.

If you forward messages, SPF will break. Many sites reject such
messages.
If you now rewrite the MAIL FROM, SPF will be fine but DMARC will fail
if a reject policy is set.

You may need to think about implementing ARC with a Milter.

--
kind regards
Marco

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