What is WHOIS?
WHOIS is the public registration record of a domain: which registrar holds it, when it was registered, when it expires and which nameservers it uses. RDAP (Registration Data Access Protocol) is its structured successor, and this tool queries RDAP. Since GDPR, the registrant's own contact details are usually redacted.
Reading the result
You get the registration status, the registrar, the registration date and age, the expiry date, whether DNSSEC is signed and the nameservers. A field the registry does not publish says so. When a lookup fails, the reason is shown, because a registry that is down and a top-level domain with no RDAP service call for different next steps.
Beat runs on the same engine, on a schedule, across all 41 checks and 25 blacklists. What it adds is asking again, noticing when an answer changes and telling you what to do about it.
Common domain registration problems
A very young domain
A domain registered in the last few weeks has no sending history. Receivers are cautious with volume from new domains, so warm one up slowly before a campaign.
An expiry date close by
If the registration lapses, mail and the website stop together. Turn on auto-renew and keep the registrar account email somewhere you read.
Nameservers you did not expect
Records edited anywhere other than these nameservers never go live. They decide where SPF, DKIM and DMARC must be published.
DNSSEC not signed
Email works without it. It is required for DANE, which publishes your mail server's TLS certificate in DNS so senders can verify it.