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Outlook.com

550 5.7.515 “does not meet the required authentication level”

Outlook.com and Hotmail require senders of 5,000 or more messages a day to pass both SPF and DKIM and to publish a DMARC record that matches the From domain. Passing DMARC alone isn't enough.

Codes: 550 5.7.515. Source: Microsoft: Fix NDR error 550 5.7.515 in Outlook.com.

What usually causes it

  • SPF passes for the email service's own domain rather than yours.
  • DKIM signs with the service's domain, or isn't turned on.
  • No DMARC record, or one that doesn't match the From domain.

How to fix it

  • Read the authentication results in a bounced message's headers to see which check failed.
  • Set up the email service to use your domain for both its bounce address and its DKIM signature.
  • Publish a DMARC record: v=DMARC1; p=none to start.
The free email check can find part of this

The free check shows your SPF, DKIM and DMARC records. Whether a service signs with your domain needs a real message's headers.

Run the free email check

Want it fixed? Our email deliverability packages start at $49 for an audit and plan. Other error codes.