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Microsoft Defender for Office 365 Blog
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Strengthening Email Ecosystem: Outlook’s New Requirements for High‐Volume Senders

Puneeth's avatar
Puneeth
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Apr 02, 2025

This applies to Outlook.com - our consumer service, which is supporting hotmail.com live.com and outlook.com consumer domain addresses.

April 29th Update - Changes have been made to the action take on messages that do not meet requirements, please see details below. Introduction In an era where email remains one of the most widel...
Updated Apr 30, 2025
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Puneeth's avatar
Puneeth
Icon for Microsoft rankMicrosoft
Apr 04, 2025

We don't plan to expand this to Enterprise yet. Enterprise environments have complex mail flows that can break DMARC. We’ll get there eventually, but not with this release. This is focused only on Microsoft's consumer services.

For DMARC, a minimum of p=none is required. Over time, we aim to move toward stricter authentication without causing major email disruptions.

jcowart's avatar
jcowart
Copper Contributor
Jun 24, 2025

What you've missed is that those "complex mail flows" exist on the sending side as well, making compliance with these guidelines challenging in the absurdly short timeframe you gave the community and even undesirable.