Free tool
DMARC Record Generator
Choose a policy and where reports should go. Import your current record first to keep every existing report address.
Frequently asked questions
+Which DMARC policy should I start with?
Start with p=none and a report address. Once reports show that all your legitimate services pass, move to quarantine and then reject.
+Will changing my DMARC record stop my current reports?
Not if you keep the existing rua addresses. Use Import current record and the generator merges them into the new record.
+Where do I publish the DMARC record?
As a TXT record at _dmarc.yourdomain.com. There must be exactly one; edit the existing record instead of adding another.