Free tool
Free SPF / DKIM / DMARC validator
Check your domain's email configuration in one click. Identify deliverability issues.
Understanding email authentication
SPF
Sender Policy Framework defines which servers are allowed to send emails for your domain. Add a TXT record in your DNS.
DKIM
DomainKeys Identified Mail adds a cryptographic signature to your emails, proving they come from your domain and haven't been modified.
DMARC
Domain-based Message Authentication tells receiving servers what to do if SPF or DKIM fail: nothing, quarantine, or reject.