Jeffrey Goldberg wrote:
[relays keeping the MAiL FROM of the submitter]
There is very good reason to offer this service.
Yes, it works for you because you added the /24 of
the relays to your sender policy. There's nothing
wrong with this service if the senders know what
they are doing and publish a corresponding sender
policy.
Sorry for being long winded, but I don't think
that the service your ASP provides is so bizarre.
It could be a problem for domains without a sender
policy and without MX under Meng's new no-MX-rule.
But now that I've seen your example this should be
a rare case: If a small domain sends mail via a
smtp relay (i.e. not a MSA fixing their MAIL FROM),
then they most probably have an MX, and therefore
the no-MX-rule can't cause a FAIL.
If they have only a smtpd (no MX), they could add
a redudant MX record to bypass the no-MX-rule.
And if they have nothing at all the FAIL of the
no-MX-rule would be (more than) appropriate. In
this rare case the provider of the smtp relay
should explain the problem to his user. Or Weng
simply adds this as a special case to why.html
Or the provider of the relay could automatically
enforce the rule: no MX and no sender policy =>
behave as MSA (= fix MAIL FROM), otherwise relay.
Bye, Frank