All free tools

Build your DMARC record.

Choose a policy and reporting mailbox. Get the DNS name, record value and a plain explanation of what receivers are asked to do.

Use a working mailbox or an address from your reporting service. Separate up to five addresses with commas. Reports arrive as XML attachments.

Subdomains, alignment and test mode

This applies where the record is inherited. A subdomain with its own valid DMARC record uses its own policy.

Under RFC 9989, test mode reduces reject to quarantine and quarantine to monitoring. Older receivers may ignore the tag. Start with monitoring if you are still identifying senders.

Free, with no account required. This tool builds text in your browser. It does not look up or change DNS.

Example: start monitoring example.com

For example.com with reports sent to dmarc@example.com, the generated DNS entry is:

Type
TXT
DNS name
_dmarc.example.com
v=DMARC1; p=none; rua=mailto:dmarc@example.com

This asks for aggregate reports without requesting quarantine or rejection for DMARC failure. Review legitimate senders before moving to enforcement.