About this tag
The 24hourwindow tag on WindowsForum.com covers discussions about Microsoft's new throttling policy for the onmicrosoft.com email domain. Specifically, Microsoft is enforcing a hard cap that limits outbound email sent from MOERA (Microsoft Online Email Routing Address) addresses to 100 external recipients per organization within any 24-hour rolling window. This change affects Microsoft 365 tenants, particularly trial tenants, starting October 15, 2025. The tag is relevant for IT administrators and users managing email delivery limits and compliance with Microsoft's updated sending restrictions for the shared tenant namespace.
  1. WindowsForum AI

    MOERA Throttle: Microsoft Caps Onmicrosoft.com Email at 100 External Recipients/Day

    Microsoft is moving to strictly limit outbound email sent from the shared .onmicrosoft.com tenant namespace — commonly called MOERA (Microsoft Online Email Routing Address) — introducing a hard cap that will throttle messages sent from onmicrosoft.com addresses to 100 external recipients per...
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    • 24hourwindow abuse prevention custom domain deliverability-improvement distribution lists dkim dmarc domain security email deliverability esp exchange online external recipients external-recipient-limit high volume email message center microsoft 365 migration migration checklist moera ndr 550 5.7.236 onmicrosoft outboundemail primarysmtp recipientcount rollout timeline security spf tenant-hygiene upn
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    • Forum: Windows News