On 27.11.25 12:46, Endre Szabo via mailop wrote:
Final rDNS server of reversedns.vultr.com has the zone improperly
configured (serving from in-addr.arpa. instead of
203.138.155.in-addr.arpa.) which violates RFC 1034 section 4.2.2. I'm not
saying that's Google's problem with you, but with strict enough checking
it definitely can be a policy violation.
On top of that, the parent NS also has the zone delegated as
148.203.138.155.in-addr.arpa instead of 203.138.155.in-addr.arpa which is
also an incosistency.
This is at least partially correct:
203.138.155.in-addr.arpa servers (rns1.vultr.com and rns2.vultr.com)
seem to delegate all individual reverse records from
203.138.155.in-addr.arpa (maybe more than that) to reversedns.vultr.com.
This way of reverse delegation for zones less than /24 was proposed long ago
by DJ Bernstein. However for it to be correct it really should provide
separate zones for each delegated IP.
sane people should use RFC2317 for delegation of less than /24
and delegate whole 203.138.155.in-addr.arpa.
But I guess you got the issue, the reverse DNS delegation is braindead and
also creates SPoF.
On Thu, Nov 27, 2025 at 10:26:10+0000, ml+mailop--- via mailop wrote:
Does google have broken DNS resolvers?
550-5.7.25 [155.138.203.148] The IP address sending this message does not have a
550-5.7.25 PTR record setup, or the corresponding forward DNS entry does not
550-5.7.25 match the sending IP. As a policy, Gmail does not accept messages
550-5.7.25 from IPs with missing PTR records. For more information, go to
550-5.7.25 https://support.google.com/a?p=sender-guidelines-ip
550-5.7.25 To learn more about Gmail requirements for bulk senders, visit
550 5.7.25 https://support.google.com/a?p=sender-guidelines.
00721157ae682-78ad0d509c9si5517897b3.115 - gsmtp
dig +short -x 155.138.203.148
veps.esmtp.org.
dig +short veps.esmtp.org
155.138.203.148
If it would be a temporary problem at their side would they
at least generate a 4xy reply?
--
Matus UHLAR - fantomas, [email protected] ; http://www.fantomas.sk/
Warning: I wish NOT to receive e-mail advertising to this address.
Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu.
Linux is like a teepee: no Windows, no Gates and an apache inside...
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