Why are emails failing DMARC alignment with Symantec Email Security Cloud after a DMARC policy update to p=reject?
Summary
What email marketers say6Marketer opinions
Email marketer from EmailGeek Community suggests the issue might stem from a tenant-level configuration within Symantec Email Security.cloud, particularly affecting how it handles DMARC alignment checks. This could be due to specific settings or rules applied at the tenant level that are not correctly processing the updated DMARC policy.
Marketer from Email Geeks advises the sender to have a friendly recipient escalate the issue through Symantec's support chain, as it might be a bug or systems integration issue.
Email marketer from MXToolbox Forum highlights that DNS propagation issues after updating a DMARC record can temporarily cause failures, as not all servers may have the updated information immediately.
Email marketer from Reddit mentions that configuration errors in SPF or DKIM records can cause DMARC failures, especially after enacting a stricter policy. It suggests double-checking these records for accuracy and completeness.
Email marketer from StackOverflow suggests verifying that the domain used for DKIM signing matches the domain in the 'From:' header. A mismatch will cause DMARC to fail, especially with a reject policy.
Email marketer from StackExchange explains that anti-phishing technologies, such as URL rewriting, modify email content after DKIM signing, leading to DKIM verification failures and, subsequently, DMARC alignment issues. Symantec Email Security.cloud may be employing such technology.
What the experts say4Expert opinions
Expert from Word to the Wise explains that setting a DMARC policy to `p=reject` without fully understanding the implications can lead to false positives. Symantec's actions might trigger rejections if the sender's authentication isn't perfectly aligned, and it's crucial to monitor DMARC reports to identify and rectify these issues.
Expert from Email Geeks explains why a `p=quarantine` policy results in delivery (with potential spam folder placement), while `p=reject` causes bounces.
Expert from Email Geeks suggests the issue might be due to anti-phishing tech rewriting URLs, breaking DKIM. Recommends checking if the recipient's company uses this solution and if there's a misconfiguration trusting Symantec's changes.
Expert from Spam Resource explains that email forwarding can often break DMARC. When Symantec Email Security Cloud rewrites URLs or modifies content for security, it can invalidate the original DKIM signature. If the forwarding service doesn't properly handle DMARC, the message may fail DMARC checks at the recipient.
What the documentation says5Technical articles
Documentation from DMARC.org highlights that a `p=reject` policy instructs receiving mail servers to reject emails that fail DMARC checks. If the emails are genuinely failing alignment, this setting will cause bounces. Incorrect configurations or issues with email authentication (SPF/DKIM) are primary causes.
Documentation from Microsoft support explains the importance of checking SPF and DKIM alignment modes. If the alignment is set to 'strict' but is failing even slightly, it will lead to a DMARC failure and a reject action based on the policy.
Documentation from RFC explains that DMARC relies on the proper interaction of SPF and DKIM. If either of these mechanisms fails, the email will not align with DMARC, and the policy will be enforced.
Documentation from Mimecast states that the interaction between DMARC policies and email security services can sometimes lead to unexpected results. If Symantec is altering the emails in transit, it can interfere with the DMARC authentication process.
Documentation from Broadcom Support explains that issues can arise due to changes in how Symantec Email Security.cloud processes emails after a DMARC policy update to p=reject. This may involve URL rewriting or content modification for anti-phishing measures, leading to DKIM breakage and subsequent DMARC failures.