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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
Icon for Microsoft rankMicrosoft
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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rahulsharmacvent's avatar
rahulsharmacvent
Copper Contributor
May 01, 2025

Please help me understand:

Is the 5000 email threshold counted per Microsoft domain or combined across hotmail.com, outlook.com, and live.com?

If a sender crosses the threshold once, are they permanently considered a bulk sender?