Support – DMARC

If you see an DMARC warning message when using the Media Contacts Database distribution tool this means we have detected from your company’s DNS records that your domain is using the DMARC (Domain-based Message Authentication, Reporting & Conformance) email authentication policy and reporting protocol.

To enable access to the email distribution section on our media database conflicting sender authentication measures must be removed.

How to fix this
Authorise ResponseSource to send mail on your behalf by having your DNS administrator add a CNAME record for rs-dkim._domainkey$domainname going to

What the DNS change does
When we send mail on your behalf the receiving mail server can see that emails ‘from’ your domain but actually originating from ResponseSource servers are valid – because they have been signed by that domain key.

What is DMARC?
DMARC helps email receivers determine if the purported message “aligns” with what the receiver knows about the sender. If not, DMARC includes guidance on how to handle the “non-aligned” messages. For example, assuming that a receiver deploys SPF and DKIM, plus its own spam filters, the flow may look something like this:

(image courtesy of

For the full and comprehensive details on DMARC visit

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