Why am I seeing an ‘External Verification Failure’ in my DMARC reports and how can I fix it?

Why am I seeing an ‘External Verification Failure’ in my DMARC reports and how can I fix it?

When you set up DMARC, the RUA (aggregate) and RUF (forensic) tags tell email receivers where to send your DMARC reports. If the domain in those email addresses hasn’t been verified, you’ll see an “External verification failure” warning.

Quick Takeaways

• The warning means the domain in your RUA/RUF tags can’t receive DMARC reports yet.
• Fix it by adding a specific TXT record to the external domain’s DNS.
• The TXT record format is: example.com._report._dmarc.example2.com with value v=DMARC1;.
• Only domains you control can be verified – free‑mail services like Gmail can’t be used.
• After publishing the TXT record, reports will start flowing to the designated inbox.
• Use Palisade’s DMARC Record Checker to confirm the fix.
• Check related protocols: SPF, DKIM, and BIMI.

Frequently Asked Questions

What does the “External verification failure” warning actually mean?

It indicates that the domain listed in your RUA or RUF tag hasn’t published the required verification TXT record, so receivers can’t deliver DMARC reports to that address.

Why can’t I use a Gmail address for RUA/RUF?

Gmail is a free‑mail domain you don’t control, so you can’t add the verification TXT record it requires. Use a domain you own and can edit its DNS.

How do I create the verification TXT record?

In the DNS zone of the external domain (the one after the @ in your report address), add a TXT record:

• Host/Name: yourdomain.com._report._dmarc.externaldomain.com
• Value: v=DMARC1;

How long does it take for the verification to work?

DNS propagation can take from a few minutes up to 48 hours, depending on your TTL settings. After that, the warning should disappear.

What tools can I use to verify my setup?

Run Palisade’s DMARC Record Checker. It will confirm that the external verification TXT record is visible and that reports will be delivered.

Additional FAQs

Do I need separate TXT records for each reporting address?

No. One verification record that references your domain is enough for all RUA/RUF addresses on the same external domain.

Can I use a subdomain for report collection?

Yes, just ensure the subdomain’s DNS includes the verification TXT record matching the full address.

What happens if the external domain never verifies?

DMARC reports will be dropped for that address, and you’ll lose visibility into authentication failures for your domain.

Is the verification record visible to the public?

Yes, it’s a public DNS TXT record, but it only contains v=DMARC1;, which poses no security risk.

Can I automate the creation of these records?

Many DNS providers offer API access. You can script the creation of the verification TXT record as part of your DMARC deployment pipeline.