Multiple A and PTR and the "main" ones?
david at blue-labs.org
Fri Sep 11 14:54:52 UTC 2015
We are also one of those services that will reject mail if DNS records
don't line up sufficiently to a) satisfy RFC requirements for DNS and b)
are clearly mismatched with your DNS A/MX/PTR/SPF and who you pretend to
be in HELO/EHLO
Those two simple rules block more than 92% of incoming spam attempts.
"generics" tend to fall into that pit nearly 100% of the time. If your
DNS can simply say in MX/SPF that you are legit, you easily avoid that pit.
Blocking the majority of spam is really easy if we simply require
adherence to what is actually mandated in RFC and a pinch of sensible
thinking about DNS.
On 2015-09-11 14:33, Lightner, Jeff wrote:
> Actually some mail servers DO check not only that a PTR exists but also that it is not "generic".
> Every once in a while we get someone complaining because one of the big sites (Ebay?) refuses to accept their email due the "generic" (as defined by that site's policies) nature of our PTR. We typically ignore that because we've never seen this complaint from other mail servers and no one has ever provided a business use for the one site that is complaining.
> Other than that I've never seen any complaint about what the actual PTR is so I can't imagine why you'd need more than one for the same IP. Just pick the one that helps identify you for anyone that cares to look at IPs vs names.
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