Microsoft Joined the DMARC Club — Is Your Domain Ready?

Google and Yahoo dropped their email authentication hammer in February 2024. Microsoft watched that unfold, nodded slowly, and then did the same thing on May 5, 2025. If your domain hasn’t sorted out SPF, DKIM, and DMARC by now, a chunk of your outbound mail is already being rejected — silently, with no bounce to show for it. What Microsoft Actually Requires For anyone sending 5,000 or more messages per day to Microsoft consumer addresses (@outlook.com, @hotmail.com, @live.com), the requirements are: ...

May 31, 2026 · 4 min