Create the provider/planner-approved TXT record at _dmarc.yourdomain.
Step by Step
- Make sure SPF and DKIM are understood and working first.
- Decide on the initial DMARC policy and reporting needs.
- Create a TXT record at _dmarc.
- Enter a syntactically valid value beginning with v=DMARC1.
- Start conservatively when appropriate and monitor results before enforcing a stricter policy.
If That Doesn't Work
- A strict DMARC policy can reject legitimate mail if all sending systems are not configured correctly.
- DMARC deployment should account for every legitimate sender.