There is no global reputation property stored in DNS. Different services score sending history, malware reports, links, complaints, ownership, and age using private datasets and incompatible rules. A generic number cannot tell you which of those systems contributed to it or how stale the observation is.
This checker takes the opposite approach. It shows facts that can be reproduced: whether the domain exists, whether it accepts mail, whether known temporary-mail infrastructure is involved, when the registry says it was registered, and whether SPF and DMARC are published. A severe routing or disposable-provider signal matters more than an optional authentication record, and the interface keeps those meanings separate.
How to investigate an unusual result
Open the WHOIS/RDAP lookup for the full normalized registry timeline, then compare individual answers with the DNS lookup. If sender authentication is the concern, the SPF checker and DMARC checker explain the policies rather than merely testing whether a TXT record exists.
Do not use domain age alone to block users or payments. New organizations need new domains, and attackers also acquire established names. Treat age as one reason to ask for stronger evidence, not as a substitute for it.