Is Microsoft’s SNDS network re-attestation email legitimate?

The year 0001 is probably a bad or missing date value in Microsoft’s message template or backend data, not a meaningful deadline. I would treat the date as a software or formatting error and confirm the request directly through the SNDS portal before taking action.

The aka.ms link appears to lead to Microsoft’s legitimate SNDS re-attestation page, and SNDS is a real Microsoft service used for mail-delivery reputation. Still, it’s safest to open the SNDS site independently rather than relying on the email link, then check whether the listed IP and requested action appear in your account.

Several people received the same message with SPF and DMARC passing. That makes ordinary spoofing less likely, although authentication alone doesn’t prove the message content was well written or intentionally sent. The formatting looks like a Microsoft notification template that was published incorrectly.

Check the full authentication results, especially whether DKIM was aligned and whether DMARC passed. One report indicated SPF and DMARC passed while DKIM was aligned but not authenticated, suggesting the message may have originated from Microsoft’s notification infrastructure even if the email itself was poorly configured.