Outlook.com starts rejecting email from domains without DMARC, without announcing it

Mon, 09 Nov 2026 00:00:00 +0000

Since November 5, Outlook.com (and with it Hotmail, Live and MSN) has been bouncing part of the mail sent from domains that don’t publish a DMARC record. Thomas A. Johnson, from MailRoute, spotted it in their own outbound logs that same day, and other administrators started reporting it at the same time.

The odd part is that Microsoft hasn’t said a word. No notice on its postmaster portal, no blog post, no service health entry. It just started happening.

Email on Antonio Cortés (DrZippie)

Outlook.com starts rejecting email from domains without DMARC, without announcing it