Check an Email Address Online
There is nothing to install. Paste an email address and the check runs in your browser: first against a built-in list of official company domains, then live lookups in Google Public DNS, domain registration data (RDAP) and Wikidata.
You see a clear result, real, fake lookalike, personal account or unknown, with the reasons, plus the domain’s age, mail server, SPF and DMARC. Use it on your phone the moment a suspicious email arrives.