Domain tester
The Mailcheer domain tester reads your SPF, DKIM and DMARC records and tells you which are present, which are missing, and what to fix — no account needed.
The domain tester is a free public tool from Mailcheer: enter a domain name, and it reads its DNS authentication records to show you where you stand. Free, no account needed, on the SPF, DKIM and DMARC checker page.
What it reads
The tester queries the domain's public DNS in real time:
| Check | What is verified |
|---|---|
| SPF | A TXT record starting with v=spf1 at the domain root. |
| DMARC | A TXT v=DMARC1 on _dmarc.<domain>, and the declared policy (p=none, quarantine or reject). |
| DKIM | The presence of a public key on <selector>._domainkey.<domain>, by trying the most common selectors. |
Results arrive within a few seconds (maximum delay: 4 s).
Reading the result
- DKIM and selectors: unlike SPF and DMARC, a DKIM record is published under a "selector" chosen freely by the sending tool. The tester tries the generic selectors (
default,dkim,mail…) and those of the main platforms: Google Workspace, Microsoft 365, Mailchimp, SendGrid, Brevo, Mailjet, Zoho, Proton Mail, Fastmail, Postmark… If your tool uses a custom selector not on this list, your DKIM may be reported as missing even though it exists. - The tester reads your domain's configuration — not the sender's reputation or the email content. A perfectly configured domain can still land in spam for other reasons: see Deliverability.
- The result reflects the DNS state at the time of the test: after a change, propagation can take from a few minutes to 48 hours.
What to do with an incomplete result
A missing SPF, DKIM or DMARC record is fixed by publishing the right DNS records. If the domain is yours and you use Mailcheer, the verification wizard generates everything, then checks that every record is in place. To understand each record type: DKIM, SPF and DMARC.