Why am I receiving DMARC failure reports when my email authentication seems correct?
Summary
What email marketers say10Marketer opinions
Email marketer from Email Geeks explains that the DMARC failure report may be a typical case of forwarding and if the email originated from the MS IP, it can be ignored.
Email marketer from ReturnPath shares that issues with hosted ESP configurations can trigger DMARC failures. This is often due to shared IP addresses and varying authentication practices among different senders on the same platform. They suggest ensuring your ESP properly supports DMARC and offers dedicated IP options.
Email marketer from StackOverflow answers that DMARC failures can happen when email is forwarded, because the forwarding server is not authorized to send emails on behalf of your domain. As a result, the SPF record check will fail, and the DMARC policy will be triggered, generating a failure report.
Email marketer from AuthSMTP shares that receiving DMARC failure reports despite correct authentication configurations could be because your configuration isn't fully propagated across all DNS servers. They suggest using online DMARC checkers to verify DNS records from multiple locations.
Email marketer from Email on Acid shares that even with a valid SPF record, DMARC can fail if the 'Return-Path' domain (used for SPF checks) doesn't match the 'From' domain. They recommend ensuring SPF alignment by using a 'Return-Path' domain that matches the 'From' domain, often requiring a custom 'Return-Path' configuration.
Email marketer from Reddit shares that a primary reason for receiving DMARC failure reports is email forwarding. When an email is forwarded, the SPF record check fails because the email is no longer being sent from an authorized server, and DMARC then flags the email as a failure.
Email marketer from SparkPost explains that understanding SPF and DKIM alignment modes (strict vs. relaxed) is crucial for DMARC. If either SPF or DKIM is set to strict alignment and fails, DMARC will fail, even if the other passes with relaxed alignment. They suggest reviewing your DMARC policy and authentication configurations.
Email marketer from EasyDMARC explains that common causes for DMARC failure reports despite proper authentication include email forwarding, using multiple email sending sources without proper SPF/DKIM configuration for each, and incorrect DNS settings. They recommend auditing your sending sources and ensuring correct SPF/DKIM alignment.
Email marketer from EmailMarketingForum.com explains that some regional email providers (like in Europe or Asia) have stricter rules regarding email authentication. Failure to comply with these regional standards can cause DMARC failures, even if your general settings appear correct. They advise researching specific regional compliance requirements.
Email marketer from Mailjet shares that DMARC failures can happen even with correct SPF and DKIM records due to forwarding, which changes the sending server and invalidates SPF. They also mention issues with DKIM key rotation and alignment problems between the 'From' header and DKIM signature as potential causes.
What the experts say4Expert opinions
Expert from Word to the Wise shares that if you are seeing DMARC failures and your mail is forwarded, the issue is that forwarding changes the source IP address and breaks SPF. They also share that with DKIM, it's important to sign with the same domain as your From: address.
Expert from Email Geeks explains the user should delete the old SPF record and that the TXT record for email.kiusys.com is a broken DKIM entry, and provides the format it should look like.
Expert from Spam Resource explains that the number one reason why DMARC fails even though SPF and DKIM pass is because of mail forwarding. This happens because the forwarder isn't authorized to use your domain.
Expert from Email Geeks states that DKIM looks to be failing.
What the documentation says4Technical articles
Documentation from Google Workspace Admin Help explains that receiving DMARC reports indicates that emails are failing DMARC checks. Even if authentication seems correct, the reports highlight discrepancies between the sender's claimed identity and the actual sending source, often due to forwarding or misconfiguration.
Documentation from DMARC.org highlights that misaligned identifiers are a primary reason for DMARC failures. This happens when the domain in the 'From' header does not match the domain used for SPF or DKIM authentication. They also emphasize the importance of consistent domain alignment for successful DMARC validation.
Documentation from Microsoft explains that DMARC failures in Office 365 can occur due to various reasons, including misconfigured SPF records, DKIM signature issues, or emails being relayed through non-compliant servers. They advise checking the message header for detailed authentication results to identify the specific cause of the failure.
Documentation from RFC outlines that DMARC failure reports can also result from policy settings on the receiving end. If a recipient's mail server has a strict DMARC policy and your email does not fully align with their requirements (even if it passes basic SPF/DKIM), it can trigger failure reports. You may need to adjust your DMARC policy to match common receiving server requirements.