Hi everyone, Is anyone else experiencing intermittent DKIM failures when sending emails to Outlook.com? This started on May 5th.
If I resend the same message, it’s successfully delivered. By “same message”, I mean the exact same content, headers, Message-ID, DKIM signature, etc. Essentially copy/pasting the original message without any modifications. Even other messages sent in the same SMTP connection and using the same sender/DKIM key are accepted. The error message I receive is: ``` 550 5.7.515 Access denied, sending domain REDACTED-FOR-PRIVACY.COM doesn't meet the required authentication level. The sender's domain in the 5322.From address doesn't meet the authentication requirements defined for the sender. To learn how to fix this see: https://go.microsoft.com/fwlink/p/?linkid=2319303. Spf= Pass, Dkim= Fail, DMARC= Pass [SA0PR11MB4544.namprd11.prod.outlook.com 2025-05-13T15:54:59.356Z 08DD91CC42BDD986] ``` DKIM is correctly configured. I’ve verified it using multiple tools (e.g., https://aboutmy.email/, opendkim-testmsg, etc.), and we have zero issues with other providers. DMARC is set as "v=DMARC1; p=none;". I’ve opened a support ticket, but the responses so far have been generic and not directly related to the intermittent nature of the issue. Anyone else seeing something similar? Best regards, Fernando.
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