How I Stopped Worrying About Fake Signups (And Built an API Instead)

If you’ve ever built a signup flow, you’ve probably run into this at some point: You launch something… and within a few days you start seeing signups like: asdf123@mailinator.com test@test.com qweqwe@tempmail.xyz At first I ignored it. Then it started affecting things: noisy user data wasted emails skewed metrics occasional abuse That’s when I realized basic email validation wasn’t doing much. Regex isn’t enough Like most people, I started with a simple regex check. It works for catching obvious mistakes, but that’s about it. It doesn’t tell you: if the domain exists if the domain can receive email if it’s a disposable address So technically valid emails were still completely useless. What actually helped I started layering in a few additional checks. Nothing fancy — just practical stuff that could run fast enough during signup. Domain validation Make sure the domain actually exists. This alone filters out a surprising number of junk entries. MX record check Check if the domain can rec