Set up DKIM for Microsoft 365
The exact steps in the Microsoft 365 admin console, followed by a checker to confirm the record resolves once you publish it.
Steps
- Open security.microsoft.com and sign in as a global or security administrator.
- Navigate to Email & collaboration → Policies & rules → Threat policies → Email authentication settings → DKIM.
- Select the domain and read the two CNAME targets shown.
- Publish CNAMEs at selector1._domainkey and selector2._domainkey pointing at those targets.
- Set Sign messages for this domain with DKIM signatures to Enabled.
Confirm it workedDKIM checker
DNS changes take time to propagate. Check the record once you have published it.