How to set up DMARC (and stop landing in spam)

If your emails keep landing in spam, there is a good chance your domain is missing a DMARC record. Mail providers like Gmail and Outlook use three DNS records to decide whether an email really came from you: SPF, DKIM and DMARC.

What the three records do

• SPF lists the servers that are allowed to send email for your domain.
• DKIM adds a signature to every message, so the receiver can tell nothing was changed on the way.
• DMARC tells receivers what to do when a message fails those checks, and where to send reports.

You need SPF and DKIM working first. DMARC builds on them.

The record to add

Go to your DNS provider and add a TXT record with the name _dmarc and this value:

v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com

With p=none, nothing gets blocked yet. You only start receiving reports about who sends email in your name.

Moving to protection

After two to four weeks, read the reports. If every service you use (your mailbox, newsletter tool, invoicing app) passes, change p=none to p=quarantine. Failing messages then go to spam. Once you are confident, switch to p=reject.

Check your setup

Run your domain through the website checker. The email section shows whether SPF, DKIM and DMARC are in place and flags common mistakes, such as two SPF records on one domain.