At Oct 24 21:06:13 UTC, after years of being IPv4-only, Microsoft Hotmail published two IPv6 records for the hotmail.com MX record. Great! Progress! Hurrah! Except that one hour later, Oct 24 22:00:57 UTC, our IPv6 address was blocked, after just 9 emails sent, as "spam." Prior to this date, as far back as our logs go, we have had ZERO issue with the almost 700,000 emails sent and accepted by Hotmail users since May 29, 2022. So I visited the trusty Smart Network Data Service and Junk Mail Reporting Program to try to troubleshoot. Except that these two services are still IPv4-only, so I cannot even attempt to try to self-troubleshoot why Microsoft is blocking email via IPv6. I have opened a support ticket, but I figured I would see if anyone here has seend or heard or had this issue, or if any Microsoft lurkers might see this and investigate. Support request number: SR1543766049 I have not been able to find any mention in Google or elsewhere of the planned switch to enable IPv6 for Hotmail, nor any updated way to register with Microsoft with IPv6 address space. Yes, we sign with DKIM and have up-to-date SPF records with both IPv4 and IPv6 addresses. Google seems to have no issue here. Thanks All Beckman --------------------------------------------------------------------------- Peter Beckman Internet Guy beckman@angryox.com https://www.angryox.com/ ---------------------------------------------------------------------------