Show HN: Email Sleuth – Find and Verify Emails (Rust CLI)

I built this because I was tired of paying $99/month for tools like Clearbit and Hunter — and most of them don’t even verify if the email address exists. They just guess.

So I wrote a CLI tool in Rust.

You give it:

    A full name (like “Jane Smith”)

    A domain (like company.com)

It:

    Generates common email patterns (jane@company.com, jsmith@, etc)

    Scrapes the company website for any public emails

    Does an SMTP check (MX + RCPT TO) to verify if the email exists

    Scores and ranks the candidates

Why?

I wanted something fast, private, scriptable, and verifiable — not just “guesses” wrapped in a pretty UI. This has JSON in/out, works well in batch mode, and can run locally or in CI pipelines.

Notes

    Port 25 warning: SMTP verification requires outbound port 25 access. Most home ISPs block this. I’m not a networking guy, so maybe there’s a better solution — but I just run it on a GCP VM and it works fine there.

    Rust has been awesome for this: fast HTTP/S scraping, socket-level control, robust error handling, and painless multithreading. Probably wouldn’t want to write this in Python.

It’s open-source (MIT), no trackers, no signup, no web UI. Not sure if this is useful to anyone outside of that weird founder/hacker/recruiter intersection, but figured I’d share.

Would love feedback, issues, feature requests, or just a reality check.