Like this (example is from our own setup):
;; ANSWER SECTION:e.1.7.0.0.0.0.0.0.0.0.0.0.0.0.0.a.1.e.7.0.0.4.f.1.1.1.0.1.0.a.2.ip6.arpa. 3379 IN PTR mail-db8eur05on2071e.outbound.protection.outlook.com.
;; ANSWER SECTION:mail-db8eur05on2071e.outbound.protection.outlook.com. 76 IN AAAA 2a01:111:f400:7e1a::71e
However, the IPv6-address in the error below resolves to two names: ;; ANSWER SECTION:0.0.7.0.0.0.0.0.0.0.0.0.0.0.0.0.b.1.6.2.3.0.4.f.1.1.1.0.1.0.a.2.ip6.arpa. 3165 IN PTR mail-cwxgbr01on20700.outbound.protection.outlook.com.
;; ANSWER SECTION:mail-cwxgbr01on20700.outbound.protection.outlook.com. 24 IN AAAA 2a01:111:f403:707f::700 mail-cwxgbr01on20700.outbound.protection.outlook.com. 24 IN AAAA 2a01:111:f403:261b::700
If that is indeed an issue for Gmail, dan MS365 should perhaps fix this? -- Marco Op 24-04-2024 om 09:33 schreef Florian Effenberger via mailop:
Simon Branch via mailop wrote on 24.04.24 at 09:28:/550 5.7.350 Remote server returned message detected as spam -> 550 5.7.1 [2a01:111:f403:261b::700 19] Gmail has detected that this message;is likely suspicious due to the very low reputation of the sending;domain. //To best protect our users from spam, the message has been;blocked. For more information, go to; https://support.google.com/mail/answer/188131 <https://support.google.com/mail/answer/188131> im8-20020a056214246800b00696b2e6b32asi14453219qvb.337 - gsmtp/a friend of mine had a similar problem lately. DKIM, SPF, DMARC, PTR were all set up correctly, no blocklist entry.He disabled IPv6 delivery to Google and could send his e-mails with IPv4, so "domain reputation" suggest something that might not be applicable, as the sending domain per se seemed fine.I don't know how flexible you are in your configuration with MS365, but the error message suggests you connect to GMail via IPv6, so maybe the above helps.Florian
smime.p7s
Description: S/MIME-cryptografische ondertekening
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