Building a Domain Reputation API


I thought it’d be useful recently to take a list of email addresses, say from sales leads, and determine how “legitimate” the leads were. Obviously there are many pieces of information that could go into this, but the one that I thought of first was the strength of the email domain.

So, if your email is: [email protected], maybe that’s a better lead than [email protected]. But how do we rate such things quickly?

So I thought of building an API for it. A domain reputation API. Right now I’m thinking super simple:

  • A list of the domains corresponding to the Fortune 1000 companies, along with an integer representing their rank

  • A list of the top 100 colleges, along with an integer representing their rank

It’s going to be a REST API, so youd simply submit your domains via, and it’ll return back your reputation number. Same with university domains, like, or

It could also be expanded to support more types of institution; I just need lists of domains and a way of ranking them. And we could potentially add additional metrics as well–beyond just overall rank.

Anyway, what do you guys think? Useful? Any ideas on what to add?

Related posts: