Some senders pass on SPF alone

What it means

N sources, carrying N messages, authenticate with SPF and publish no DKIM signature at all. SPF does not survive forwarding: the moment a recipient auto-forwards one of these, the envelope changes, SPF fails, and there is no signature left to save it.

How to fix it

Turn DKIM signing on at each of those platforms and publish the selector they give you. DKIM travels with the message; SPF does not.

Check your own domain

This page describes the condition. To find out whether your domain has it, run the RUA test or the full checkup, which examines every record at once.

Understand it properly

This page covers one condition. For the whole picture, The DMARC guide, including how reporting works, or start at the Health Library.

Where this comes from

We judge this against RFC 9989 section 4.4.2. Every finding on this site cites the specification behind it so you can check the work rather than take our word for it.

Other RUA conditions

• You are ready to turn enforcement on
• Some of this is forwarded mail, not an attack
• Somebody is sending as you, and it is being delivered
• Unauthenticated mail is getting past your policy
• Your policy stopped forged mail
• Your own mail is failing authentication