Troubleshooting DMARC Issues: Common DMARC Problems

Fixing DMARC fail problems starts with monitoring your email traffic, confirming that all your legitimate senders are properly authenticated, and gradually enforcing stronger protection.

Follow MxToolbox's recommended steps if your DMARC setup is failing. This process will help ensure your business emails land in inboxes moving forward.

1. Start with a Monitoring Policy

Set your DMARC policy to p=none: This lets you collect DMARC reports without blocking any mail.
Enable reporting (RUA/RUF): Make sure your DMARC record includes addresses where you want to receive aggregate and forensic reports. These reports help you see which messages are passing or failing authentication.

2. Identify and Authenticate All Senders

List all services that send email for you: This includes tools like CRMs, marketing platforms, support systems, or billing systems.
Update SPF: Add each legitimate senders to your SPF record so receivers know those parties are allowed to send mail for your domain.
Configure DKIM: Ensure each service signs your messages with DKIM and that the signing domain matches the domain in your "From" address.

3. Gradually Increase Enforcement

Review DMARC reports regularly: Look for anything that's failing authentication or doesn't match your list of approved senders.
Fix issues as you find them: Update DNS records or work with providers to correct SPF and DKIM settings.
Move to stronger protection: Once legitimate traffic is authenticating correctly, move to p=quarantine then to p=reject to block spoofed mail.

4. Address Common Issues

"From" domain mismatches: Make sure the visible "From" address matches the domains you've authenticated through SPF and DKIM.
Third-party tools: Follow each email provider's setup steps to ensure their SPF and DKIM settings align with your domain.
Use subdomains when needed: For specific email types—such as outreach or marketing—a dedicated subdomain (e.g., marketing.yourdomain.com) can improve alignment and protect your main domain's email reputation.

So, How Do I Take Action?

DMARC can be difficult to set up and monitor. When deployed properly, you can receive feedback on the reasons why your email has been rejected, giving you insight into potential issues and needed changes to policy. MxToolbox Delivery Center lets you:

Monitor SPF, DKIM, and DMARC records in one place.
Know when to set up more restrictive policies for DMARC.
Host your DMARC record with us.
Get alerts when authentication fails.
Track record changes and propagation.

Learn more about our DMARC Hosting feature