DMARC Routing Failures: When Your Own IP Betrays You

Introduction: Too Much Security?

You set up SPF, DKIM, and DMARC to protect your domain. You tell the world: "Only accept emails from our official Server IP." But suddenly, the Marketing Department complains that none of their new Mailchimp campaigns are being delivered. You are experiencing a DMARC Routing Failure.

The Shadow IT Problem

This happens when a department uses a third-party tool (like Mailchimp or Salesforce) to send an email 'From' the company domain, but the IT department never added those specific IP addresses to the official SPF whitelist. The strict DMARC policy sees these IPs as unauthorized hackers and orders Google to delete the emails.

Conclusion

DMARC is powerful, but it requires perfect alignment. You must rigorously track every single IP address that is allowed to speak for your company. Audit your DMARC alignment here.