Check if an email address is valid — right now
Type any address into the checker. We validate the syntax, look up the domain's mail servers, talk to the mailbox and flag disposables — in about two seconds, free.
Enter any address to run a real verification — syntax, MX, mailbox and disposable checks.
Why bother checking an email address?
Because around one in five addresses collected online is unusable — and each one costs you twice: once in ESP fees to store and send to it, and again when the bounce chips away at your sender reputation.
Fake signups are routine
Disposable inboxes exist precisely to grab your lead magnet and vanish. They pass syntax checks and then expire — usually before your welcome email arrives.
Typos cost you real subscribers
Someone wanted your emails and typed gmial.com. Without a checker, you lose the subscriber and gain a bounce. With one, a did-you-mean prompt saves both.
Reputation damage is collective
Providers judge senders, not individual emails. Enough bad addresses and your legitimate mail starts going to spam — for your whole list.
Four layers of checking in one pass
A real email checker does more than match a pattern. MailTester runs four escalating layers on every address: RFC-compliant syntax validation, DNS and MX-record lookup to confirm the domain actually receives mail, a live SMTP conversation with the receiving server, and screening against disposable and role-account databases.
- Syntax and typo validation with did-you-mean suggestions
- Domain and MX verification — catches expired and parked domains
- Live mailbox check via SMTP, no message ever sent
An answer you can interpret, not just a checkmark
Every check returns a verdict with its evidence: each layer's result, a 0–100 quality score, and flags for disposable, role and free-provider addresses. So instead of a bare “valid”, you know it's a real corporate mailbox — or a catch-all domain that deserves caution.
- Per-layer results: syntax, MX, mailbox, disposable, role
- 0–100 quality score for nuanced decisions
- Honest “risky” verdicts where other checkers guess
Three steps, no learning curve
- 01
Enter the address
Paste any email into the checker above — no account needed to try it.
- 02
Get the full breakdown
Verdict, quality score, and the result of each individual check — syntax, MX, mailbox, disposable, role.
- 03
Need more than one?
A free account adds 100 verifications, bulk uploads and API access. Paid credits start at $19 for 5,000.
- 99%
- verification accuracy
- ~2s
- to a full verdict
- 4
- layers of checks per address
- $0
- to try it right now
What the checker examines
Syntax & format
RFC-compliant validation catches malformed addresses and the classic provider typos instantly.
Domain & MX records
We confirm the domain exists and publishes mail servers — catching expired and parked domains.
Live mailbox check
A real SMTP conversation with the receiving server confirms whether the specific mailbox accepts mail.
Disposable detection
Temporary inboxes from thousands of disposable providers are flagged on sight.
Role & free-provider flags
info@ and sales@ addresses, and free-mail domains, are identified so you know the address quality.
Quality score
All signals combine into a 0–100 score — a verdict you can set thresholds against.
A checker for every situation
Before a cold email
Confirm the prospect's address is live before your first outreach lands as a bounce.
Suspicious signups
That odd-looking registration? Check it — disposables and fakes are flagged in seconds.
Contacts gone quiet
When a customer stops responding, check whether their mailbox still exists at all.
Graduating to lists
Liked the single check? The same engine cleans entire files — up to 5M rows per upload.
We are a small startup and can't afford to spend hundreds of dollars every month on email verification. MailTester.com's flexible pricing plan works for us.
I am a fan. MailTester.com is super accurate and easy to use. I set it up and forget about it.
Why check an email address before using it?
Around one in five addresses collected on websites is unusable: typos at signup, abandoned mailboxes, disposable inboxes created to grab a discount code. Every one of them costs you twice — once when your ESP charges you to store and send to it, and again when the bounce damages your sender reputation.
Mailbox providers like Gmail and Outlook track your bounce rate closely. Cross 2% and your campaigns start landing in spam — for your real subscribers too. Checking addresses before you send is the cheapest insurance there is for email revenue.
What makes a reliable email checker?
Anyone can validate syntax with a regex. A real checker has to do the expensive part: query DNS for the domain's mail servers, open an SMTP conversation, interpret the server's response correctly, and handle evasive setups — catch-all domains, greylisting, slow servers — without guessing.
MailTester has been running that gauntlet since 2000 — far longer than any of the newer names in the space. The result is a checker that gives you a definitive answer where others return “unknown”, and an honest “risky” where others guess “valid”.
Free checker vs. full verification account
The checker on this page is the real engine — the same SMTP conversation, the same databases, the same scoring. A free account simply unlocks more of it: 100 verification credits, bulk file uploads with deduplication and segmented downloads, API access for your signup forms, and a dashboard history of every check.
Pay only for what you verify
Credits from $19, volume rates down to $0.0003 per email — and they never expire. Subscriptions bundle inbox testing and monitoring.
How many emails do you need to verify?
50,000credits
$79
$0.0016 per email
Common questions
Need to check more than one address?
Get 100 free verifications, bulk uploads and API access in two minutes.