550 5.7.1 Message rejected: Message lacks SPF/DKIM/DMARC Auth Records

jlccleo 15 Reputation points
2026-11-06T20:04:19.21+00:00

About 50% of my clients that have emailed me since yesterday are getting the message 550 5.7.1 Message rejected: Message lacks SPF/DKIM/DMARC Auth Records (AS9031519) [TY2PEPF0000AB8A.apcprd03.prod.outlook.com 2026-11-06T19:53:27.630Z 08DF3B738DE5D0FD].

I see others are also having this issue. Is this a Microsoft issue? I have a difficult time believing that all of my clients using different emails are all having issues with their email so it appears it is an issue with Microsoft.

Outlook | Web | Outlook.com | Email

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  1. Ryan Makepeace 0 Reputation points
    2026-11-09T02:29:12.82+00:00

    Same issue. Multiple senders affected. Replicated it myself from a work email that uses Google Workspace.
    Might finally be the reason to abandon Microsoft and Outlook permanently.

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  2. Yuki Amano 0 Reputation points
    2026-11-09T02:56:29.5533333+00:00

    I saw this issue Thurday 5/11/2026 night AEST only sending to Outlook.com/.au and Hotmail.com domains.
    All have valid SPF and DKIM records, domains show healthy in M365 Admin centre.

    The temp fix i found was adding a _dmarc record to the domain dns records.

    do we know what has changed and why this is now an issue?
    It would be nice to know some more information so i can go back to my unhappy clients to why things have changed. I have looked and cannot find anything from microsoft saying there is a change coming through that i have seen, but not saying it is not there.

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