Holehe

Holehe checks whether an email is attached to an account on 120+ sites. The README names Twitter, Instagram, and Imgur as examples. It talks to registration and forgotten-password endpoints and, on some sites, pulls a bit of extra public data from those flows.

The repo is megadose/holehe. You run it locally. A “yes” means that site’s signup or reset flow treated the address as already in use.

Why the reset-flow part matters

A sloppy email check is a knock on the door. Password-reset emails, “is this you?” prompts, and login alerts are how amateurs burn a target. Holehe is built around those endpoints, which is useful and also the risk. Some sites still send mail. Epieos says in a browser that it will not notify the target. I want that rule in writing before I use either one.

Setup tax

You still have to install it, keep it updated, and interpret a lot of “not registered” rows. Modules rot. Some sites start requiring extra steps and the checker goes quiet. A commercial email tool will do a worse job of teaching you how the check works and a better job of handing you a profile you can read.

I run Holehe when I cannot put the address into a third-party website, or when I am already in a terminal and I only need registration flags. For a named identity I go to Behind the Email. I only open IntelBase after that if I need stealer logs or a registration sweep.