Treat your sending MTA FQDNs as if they were separate customer domains, and configure SPF, DKIM and DMARC records for them. You'll have no problems then.
Regards, Mark -- _________________________________________________________________ L. Mark Stone, Founder North America's Leading Zimbra VAR/BSP/Training Partner For Companies With Mission-Critical Email Needs ----- Original Message ----- | From: "Eduardo Diaz Comellas via mailop" <mailop@mailop.org> | To: "mailop" <mailop@mailop.org> | Sent: Tuesday, August 27, 2024 6:56:18 AM | Subject: [mailop] Gmail not accepting bounces coming from vacation messages because of null sender and SPF/DKIM | Hi all, | | I've got a couple of complains from customers saying that the vacation | message is not being received by Gmail users. Our email service is quite | standard, with dovecot+sieve processing the email storage and | autoresponders. | | I've confirmed that the problem is true: | | 2024-08-27 11:08:09 1sisBN-002eWx-KM <= <> H=(mydovecot.host) | [172.30.6.182] P=esmtp K S=1087 | id=dovecot-sieve-1724749689-16845...@mydovecot.host | 2024-08-27 11:08:10 1sisBN-002eWx-KM ** randomgmailu...@gmail.com | R=hubbed_hosts T=remote_smtp H=gmail-smtp-in.l.google.com | [173.194.76.27] | X=TLS1.3:ECDHE_X25519__ECDSA_SECP256R1_SHA256__AES_256_GCM:256 CV=yes | DN="CN=mx.google.com": SMTP error from remote mail server after | pipelined end of data: 550-5.7.26 Your email has been blocked because | the sender is unauthenticated.\n550-5.7.26 Gmail requires all senders to | authenticate with either SPF or DKIM.\n550-5.7.26\n550-5.7.26 | Authentication results:\n550-5.7.26 DKIM = did not pass\n550-5.7.26 | SPF [] with ip: [555.555.555.555] = did not | pass\n550-5.7.26\n550-5.7.26 For instructions on setting up | authentication, go to\n550 5.7.26 | https://support.google.com/mail/answer/81126#authentication | ffacd0b8rr97d-373081420c7si4806836f8f.262 - gsmtp | 2024-08-27 11:08:10 1sisBN-002eWx-KM Frozen (delivery error message) | | | I think that sending the vacation messages with null sender is an | standard practise and the best way to avoid loops. I've found no | problems with any other email providers: only gmail is blocking this | messages. | | Does anyone have this issue? How do you deal with it? | | Best regards. | | -- | Eduardo Díaz Comellas | Ultreia Comunicaciones, S.L. | | _______________________________________________ | mailop mailing list | mailop@mailop.org | https://list.mailop.org/listinfo/mailop _______________________________________________ mailop mailing list mailop@mailop.org https://list.mailop.org/listinfo/mailop
