friend and i were curious what's actually involved in email verification services like usebouncer.com. turns out the basics aren't that complicated.

vibe coded a simple npm package in (mostly) one shot that does:

- syntax validation

- mx record lookup

- smtp mailbox check (without sending emails)

- catch-all domain detection

  npx email-reachable user@example.com

https://github.com/yolodex-ai/reachable

works as a library too:

  import { verifyEmail } from 'email-reachable'
  const result = await verifyEmail('user@example.com')

bouncer probably does way more, feedback welcome.