What is the best site or tool to do email address validation or a reverse lookup for the name attached to that email. I am working in a database for a company and they need to verify who their leads are and if they are legitimate. Also, is there an extension or plugin for Excel of Google Sheets that would allow this to be done in bulk?
I am not sure if there are any tools which do reverse email address lookup. But there surely are tools which can validate bulk leads. One such tool is Clearout, it makes sure that the email is still connected to a mail server and many other things. You can download the results in csv format.
There are a couple of online SaaS tools doing what are you looking for. It is the tool you are looking for: https://debounce.io/solutions/data-appending-and-enrichment/
You may also check this API: https://debounce.readme.io/reference/data-append