What our email verifier checks
Our email verifier goes past a simple format test. For every address it checks the syntax, the domain records (MX, SPF, DMARC) and then opens a real time SMTP conversation with the mailbox provider to read the server response, all without ever sending a message. You get a clear verdict in seconds.
- Invalid addresses: mailboxes that do not exist, so they always bounce.
- Catch-all (accept-all) domains: flagged as uncertain instead of guessed, so you decide with full information.
- Disposable and temporary emails: throwaway providers that pollute a list.
- Role-based addresses: info@, support@ and similar, which many providers block.
How the email verifier works
Three steps, no account needed:
- Enter an email address in the checker above.
- Real time analysis: we test syntax, domain and the mailbox over SMTP, live.
- Clear result: valid, invalid, catch-all or risky, with nothing left on our servers.
Why verify email addresses
Sending to addresses that do not exist drives up your bounce rate and damages your sender reputation, which pushes even your good emails toward the spam folder. Verifying first keeps your bounce rate low, protects your deliverability and makes every campaign more efficient.
Unlike other tools, MailTester Ninja stores nothing. Addresses are processed in memory to return a verdict and never saved, so there is nothing to leak and nothing to resell. Verification without a database, private by design.
Email verifier FAQ
Is the email verifier free?
Yes. One-off, individual checks are free on this page, with no signup. For professional use and higher volumes, our paid plans unlock unlimited daily verifications and API access at some of the best prices on the market. See our pricing.
Do you store the emails I verify?
No. Each address is processed in memory to return a result and nothing is stored, so there is nothing to leak or resell.
What is a catch-all address?
A catch-all (accept-all) domain accepts mail for any address, so a mailbox cannot be confirmed with certainty. We label it as uncertain instead of guessing valid.
How do you verify an email without sending one?
We open an SMTP conversation with the mailbox provider up to the recipient step, read the server answer, then stop. No message is ever delivered.
Checking the occasional address? It is free here, no signup.
Verifying lists for work? Our unlimited plans cover professional volumes at some of the best prices on the market, with nothing stored. See our pricing.