Email authentication checker
Free DMARC, SPF & DKIM checker
Enter your domain and see whether your email is set up to land in inboxes. We check SPF, DKIM, and DMARC and explain the results in plain English. No signup.
What these three records do
SPF
SPF lists which mail servers are allowed to send for your domain. Receiving servers check it to spot forgeries from servers you never authorized.
DKIM
DKIM adds a cryptographic signature to each message. It lets receivers confirm the mail really came from your domain and was not altered on the way.
DMARC
DMARC ties SPF and DKIM together and tells inbox providers what to do with mail that fails: monitor it, send it to spam, or reject it outright.
Looking for something specific? Check your SPF, DKIM, or DMARC record.
Keeping SPF, DKIM, and DMARC healthy is the part that quietly eats your time, and the part that decides whether your newsletter lands in the inbox or the spam folder. Yellaro handles all of it for you: managed Listmonk hosting with sending and deliverability included. See how it works or read why it matters.
Common questions
- What does this checker do?
- It looks up your domain's public DNS records and reports whether SPF, DKIM, and DMARC are set up, with a plain-English explanation of each. It only reads public DNS. It does not send email, log in, or store anything.
- What is SPF, DKIM, and DMARC?
- They are the three email authentication standards. SPF lists who can send for your domain, DKIM signs your mail so it cannot be tampered with, and DMARC tells inbox providers what to do when a message fails the first two. Together they decide whether your mail is trusted.
- Why does it say DKIM was not detected?
- DNS does not let anyone list every DKIM selector a domain uses, so we probe the common ones. Not detected means we did not find DKIM at those names. It does not mean DKIM is missing: many providers use a custom selector we cannot guess. To check yours exactly, open an email you sent, find the DKIM-Signature header, copy the value after s=, and run the check again with that selector.
- Is it free?
- Yes, completely free and no signup. Check as many domains as you like.