How To Find Which Platforms An Email Is On

1 - epieos.com is the fastest — it maps an address to Google, LinkedIn, Gravatar, Skype and more.
2 - Run holehe (Python CLI) — it tests 120+ services through their password-reset flows and returns only real hits.
3 - GHunt does the same for Google accounts and returns the account's own name and photo.
4 - Pull the Gravatar profile: MD5-hash the email, then load gravatar.com/avatar/[hash]?d=404.
5 - Check breach data — Have I Been Pwned, Dehashed, LeakCheck — the breach name tells you exactly which platform held the address.
6 - Search the address in quotes plus "site:facebook.com", "site:github.com" etc.
Manually: hit "forgot password" on a platform. "No account found" vs "reset sent" is a free oracle.
6 - hunter.io and skymem for corporate addresses and staff patterns.