Error: DMARC Fail

What's Causing This Error

Many reasons can result in DMARC failing. Given below are several causes that can raise a DMARC failure.

• Not setting up the DKIM signature.
• Email forwarding (email forwarding is when your message passes through an intermediary server before getting delivered to the receiving server. That results in an SPF check fail because the intermediary server IP does not match with sending server IP.)
• Your domain is forged or spoofed.
• Absence of sending sources in DNS.

Solution - Here's How To Resolve It

The solution for resolving a DMARC failure depends on the root cause of the error. So, the first step is identifying the root cause and then working upon it. For example, if the issue is with the DKIM signature, you can specify a DMARC signature for the domain. In turn, that prevents your email exchange service provider from assigning a default signature, which could have resulted in a DKIM and DMARC failure.

Suppose the issue is with your email getting forwarded. In that case, the solution is to switch to full DMARC compliance by aligning and authenticating all outgoing messages against DKIM and SPF at your organization. The most common cause for DMARC failing is the domain getting spoofed. In such a case, the fraud emails will not reach the recipient's inbox if you have enabled DMARC under the reject policy.

Finally, if you have not added the sending sources to your DNS, ensure there are entries in your DNS for all the third-party email vendors authorized to send emails on behalf of your domain.

Read more about DMARC failure and best practices here.