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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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awareness & training
email protection basics
Rockslice's avatar
Rockslice
Copper Contributor
Apr 30, 2025

Is SPF alignment required?  eg if contoso.com sends mail via MailChimp, the "From" address may be a contoso.com address, but the envelope sender will still be a MailChimp address, and with DKIM signatures for both domains.  

freddieleeman's avatar
freddieleeman
Copper Contributor
Apr 30, 2025

No, alignment of either SPF or DKIM is sufficient.