What are the steps to troubleshoot DMARC reject policy causing low email delivery rates after implementation?

When encountering low email delivery rates after implementing a DMARC 'reject' policy, the consensus is to immediately revert the policy to 'p=none' to prevent further rejection of legitimate emails. A thorough investigation into email authentication is then required. This involves analyzing DMARC aggregate reports to identify sources failing SPF and DKIM checks, correcting SPF and DKIM records to ensure all authorized sending sources are properly authenticated, and using tools like aboutmy.email and DMARC analyzers to pinpoint authentication issues. Before implementing a 'reject' policy, experts and documentation emphasize the importance of solid DMARC reporting, weeks/months of report analysis, and avoiding a 'reject' policy until authentication is confirmed and monitoring processes are in place. Additionally, one must consider the impact of a 'reject' policy on sending reputation and proactively monitor it, and check if your domain or sending IPs are on any blocklists, as DMARC 'reject' can amplify the impact of being blocklisted. It is crucial to gradually increase the DMARC policy back to 'quarantine' and then 'reject' only after confirming all legitimate email sources are correctly authenticated.

When facing email delivery issues after implementing a DMARC reject policy, the primary step is to immediately revert the policy to 'p=none' to prevent further rejection of legitimate emails. Then, thoroughly analyze DMARC aggregate reports to identify the sources failing authentication. Verify and correct SPF and DKIM records for all authorized sending sources, ensuring they are properly configured and aligned. Utilize DMARC monitoring services or tools to simplify report analysis. It's also crucial to check if your domain or sending IPs are on any blocklists, as DMARC reject can amplify the impact of being blocklisted. Gradually increase the DMARC policy back to 'quarantine' and then 'reject' only after confirming all legitimate email sources are correctly authenticated.

When a DMARC reject policy leads to low email delivery rates, the primary recommendation is to immediately revert to a 'p=none' policy. This stops legitimate emails from being rejected. Before implementing a 'reject' policy, it's crucial to ensure thorough authentication, solid DMARC reporting, and weeks or months of analyzing these reports. Utilizing tools like aboutmy.email can help diagnose authentication issues. Furthermore, it is vital to consider the impact of 'p=reject' on sending reputation and proactively monitor it due to the potential for widespread failures if authentication isn't perfect.

When troubleshooting low email delivery rates after implementing a DMARC 'reject' policy, the primary focus should be on ensuring proper email authentication through SPF and DKIM. Documentation from Google, Microsoft, DMARC.org, and Cloudflare emphasizes that the 'reject' policy instructs recipient servers to reject unauthenticated messages, causing delivery issues if legitimate emails fail these checks. A key step involves analyzing DMARC reports and mail flow insights to identify authentication failures due to misconfigured SPF and DKIM records. The recommendation is to start with a 'none' policy, thoroughly monitor DMARC reports, and gradually move to stricter policies like 'quarantine' and 'reject' only after verifying proper authentication. It's critical to avoid setting a 'reject' policy without adequate testing and monitoring of DMARC reports and feedback loops.