Hey guys, this looks like a fun one. I have a user, Jack Zito. He owns jackzito.com, for whom i host a vanity domain. Jack wants to forward his mail to hotmail, and hotmail has removed the ability to check external accounts (google's also removing this option).
There's a fashion brand, Vitaly, that's sending jack email. It comes with a VERPified sender. I forward it on, not modifying either the body or the MAIL FROM so I don't break DKIM signatures. According to microsoft, it passes DKIM and DMARC (not SPF). They still bounce it. === ---- Transcript of session follows ----- ... while talking to hotmail-com.olc.protection.outlook.com.: >>> DATA <<< 550 5.7.515 Access denied, sending domain VITALYDESIGN.COM doesn't meet the required authentication level. The sender's domain in the 5322.From address doesn't meet the authentication requirements defined for the sender. To learn how to fix this see: https://go.microsoft.com/fwlink/p/?linkid=2319303 Spf= Fail , Dkim= Pass , DMARC= Pass [BY5PR19MB4066.namprd19.prod.outlook.com 2026-05-22T20:45:20.818Z 08DEB7A2AF3393C5] [SJ0PR13CA0172.namprd13.prod.outlook.com2026-05-22T20:45:20.824Z 08DEB71A0186A5A0] [CO1PEPF00012E62.namprd05.prod.outlook.com 2026-05-22T20:45:20.839Z 08DEB6EE93094541] 554 5.0.0 Service unavailable === And the VERPified sender, also bounces, so they won't stop sending this stuff: .. while talking to mx.sendgrid.net.: >>> DATA <<< 550 Mailbox not found 550 5.1.1 <bounces+1998576-78a8-vitaly=jackzito....@u161779.wl030.sendgrid.net>... User unknown <<< 503 Must have valid receiver and originator Reporting-MTA: dns; quark.gushi.org Received-From-MTA: DNS; prime.gushi.org Arrival-Date: Fri, 22 May 2026 20:45:20 GMT === Now note, vitaliydesign.com has p=quarantine (not reject), so the "correct" action here is for hotmail to accept it, mark it as spam, and send an RUA along. _dmarc.vitalydesign.com. 3600 IN TXT "v=DMARC1; p=quarantine; rua=mailto:[email protected]"; Failure on every level! And of course, you'd think being a large mailbox provider, MS might have someone on this list? Based on the issues JL has been seeing, that's a negative, ghost rider. (slow clap, again) How are these companies so bad at this? Dan _______________________________________________ mailop mailing list [email protected] https://list.mailop.org/listinfo/mailop
