free tool
Free email verifier
Type an address and we ask the domain’s mail server whether that mailbox exists, then ask about a made-up address to rule out catch-all domains. Nothing is ever sent, and an answer we can’t trust says “unknown” instead of guessing.
how it works
How the email verifier works
- 01
Syntax and typos
The address is parsed the way mail servers parse it, and common domain typos (gmial.com) are flagged.
- 02
Domain and MX
We look up the domain’s mail servers. No domain, no MX or a “null MX” means mail can’t be delivered at all.
- 03
Ask the mail server
We open an SMTP conversation with the primary mail server and ask about the address with RCPT TO, then hang up before any message is sent.
- 04
Catch-all test
We ask about a random address at the same domain. If that is accepted too, the domain accepts everything and the answer is “risky”, not “deliverable”.
What the results mean
- deliverable
- The server accepts this address and refuses made-up ones. Safe to send.
- undeliverable
- No such mailbox, a disabled one, or a domain that can’t receive mail. It would bounce.
- risky
- Catch-all domain, full mailbox or disposable inbox. Mail may arrive; nobody can confirm a person reads it.
- unknown
- The server greylisted us, refused to answer or timed out. We say so rather than guess.
faq
Email verifier: common questions
How do you check if an email address exists without sending an email?
Mail servers say whether they accept a recipient before any message is sent. We connect to the domain’s mail server, give the address in RCPT TO, read the reply and disconnect. No message, no notification to the owner.
How accurate is it?
For most domains the mail server’s answer is definitive. Where it isn’t — catch-all domains, greylisting, servers that refuse to answer checks — we report risky or unknown with the reason instead of guessing. A confirmation email with a link remains the only 100% test.
What is a catch-all domain?
A domain whose mail server accepts mail for every address, whether or not the mailbox exists. A check can’t confirm individual mailboxes there, so we report them as risky.
Why does an address come back as unknown?
Some servers greylist first-time senders (“try again later”), rate-limit checks or refuse them outright. None of that says anything about the mailbox, so we answer unknown. For greylisting we retry in the background: check again in a few minutes.
Do you store the addresses I check?
No. Results are cached for a day under a keyed hash of the address so repeated checks don’t hit the mail server again; the address itself is never stored or logged.
How many addresses can I verify for free?
20 a day on this page. With a free API key you can verify from your own code, 100 a day on the free tier and more on paid tiers.