MailTester Ninja Reviews — Discover what people think of this product.

MailTester Ninja is a small, fast email verifier built for people who send at volume and are tired of paying per address.

Paste a list, drop a CSV or call the API, and every address gets checked the honest way: we ring the mail server that owns it, ask if the mailbox is there, and hang up before anything is sent. Each result comes back with a plain verdict and the reason behind it: deliverable, dead, throwaway, or a catch-all domain we will not pretend to be sure about.

Why makers like it:

• Flat pricing. From $6.99 a week, you can run 100,000 checks every day, with no credits to top up.
• Privacy by default. We do not keep the addresses you check, not even for a day.
• Developer friendly. One GET endpoint with JSON answers, packages on npm and PyPI, an OpenAPI file for your tools or your AI agent, and guides for no-code platforms.
• Free to try. A handful of free checks in the browser, plus a free API tier, no card required.

Clients who clean their lists before a campaign tell us their bounce rate ends up below 1%.