Den 04-03-2024 kl. 01:17 skrev Gareth Evans via mailop:
Given:
Received: from atlas.bondproducts.com (unknown [23.24.6.165])
by mx6.messagingengine.com (Postfix) with ESMTP id ...
[...]
Received: from users.shellworld.net (users.shellworld.net [50.116.47.71])
by atlas.bondproducts.com (Postfix) with ESMTP id ...
atlas is (I think) a relay in this context.
$ dig -x 23.24.6.165
;; ANSWER SECTION:
165.6.24.23.in-addr.arpa. 3600 IN PTR
23-24-6-165-static.hfc.comcastbusiness.net.
What I am really asking is, if
23-24-6-165-static.hfc.comcastbusiness.net
actually resolved to 23.24.6.165 (same IP as atlas...),
Yes.
The iprev / FcRDNS check would succeed, if
"23-24-6-165-static.hfc.comcastbusiness.net" had an A record pointing to
"23.24.6.165".
The first line from your quote above would then turn in to:
Received: from atlas.bondproducts.com
(23-24-6-165-static.hfc.comcastbusiness.net [23.24.6.165])
However, ...
would delivery be expected to succeed,
Having a successful iprev / FcRDNS check doesn't guarantee successful
delivery.
or does the host in the PTR also have to be atlas.bondproducts.com?
I don't know if the operator can get Comcast to add the above A record
though.
Even if the operator could, the PTR record still has signs of being
generic / auto-generated, which may be able to cause other issues,
depending on the strictness of the receiver.
The best recommendation anyone could give, would be for the operator to
make a request with Comcast, asking them to change the PTR record for
the IP address to "atlas.bondproducts.com", so it matches their own (the
actual operator's) domain, and not their provider's.
My own personal preference would however go one step further, and prefer
a total change of the configuration, to something like
"mail.bondproducts.com", if it is truly a mail server.
I hope the above gives you the clarity that you have been seeking.
--
Med venlig hilsen / Kind regards,
Arne Jensen
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