About MailHealthKit

MailHealthKit provides free tools to diagnose your email domain. The first tool is the SPF Checker, which looks up a domain's SPF and DMARC records, validates them and counts SPF DNS lookups.

How it works

Checks run on our server using public DNS lookups only. We don't send email, connect to your mail servers, or visit websites you enter. Each result shows the records we found and the evidence behind every observation, so you can verify it yourself.

What results mean

Results are diagnostic observations of published DNS records at the time of the scan. They are not a guarantee of email delivery or security. When a DNS lookup fails, we say the result is incomplete rather than guessing.

What isn't checked yet

• DKIM, which requires the selector used by your sending service
• Blocklists and sender reputation
• Deliverability and inbox placement