Email checker & validator
Validate an address's format and flag disposable domains, role accounts, free providers and common typos — instantly, in your browser. Free, no signup.
Format, disposable domains, role accounts, free providers and typos are checked instantly in your browser. The live check looks up the domain's mail servers (MX) to see if it can receive email at all. Full mailbox verification runs inside Autocloz.
Enter an email to see a breakdown.
The five checks that run as you type
The first check is format: one at-sign, no spaces, something in front of it, and a domain with a dot and at least two characters after it. The pattern is deliberately practical rather than an exhaustive reading of the email specification, because pasted addresses fail on spaces and missing dots, not on exotic legal syntax. A failed format stops the analysis there.
Four more checks then run, each against a fixed list. The domain is compared to a table of near-miss spellings of the large consumer providers, and the correction is offered back. It is checked against known disposable hosts. The part before the at-sign is matched against function words such as info, support, billing and noreply. Finally the domain is matched against free consumer providers — a note about signal quality, not about deliverability.
What the live domain lookup adds, and what it cannot settle
The live button appears once the format passes and asks the domain one question: does it publish mail servers. A domain with MX records can accept email; one with none bounces everything, which is worth learning before a bulk import. That lookup runs on the server, so it needs a connection — when it is unavailable the tool says so, and it clears itself the moment you edit the address.
What it cannot settle is whether one specific mailbox exists. That needs a conversation with the receiving server about that individual recipient, and many providers answer such probes ambiguously on purpose. A clean address on a healthy domain may still belong to someone who left last year.
Reading the verdict at the top of the card
The headline collapses the checks into one of three verdicts.
- Looks good
- Format is clean, the domain is a company domain, and the local part reads like a person. Nothing here argues against sending.
- Deliverable but worth a look
- A softer flag fired — a suspected typo, a shared function inbox, or a consumer provider where you expected a company. Read the reason and decide; none of these make the address invalid.
- Risky, do not send
- Reserved for disposable hosts and for anything that failed the format check. These cost a bounce and return nothing, so drop them.
Where a single-address check fits in list hygiene
Checking one address by hand is a spot check — useful when a form submission looks wrong or a reply bounces and you want the reason. List hygiene is a different job: run the same checks across every row, then set policy on whether shared inboxes belong in outbound at all, and how many bounces a campaign may take before it pauses itself.
Email checker FAQ
What does this email checker do?
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It validates an address's format and flags four risk signals in your browser — disposable/throwaway domains, role-based accounts (info@, support@), free/personal providers, and common domain typos (like gmial.com). It can also run a live check that looks up the domain's mail servers (MX) to confirm the domain can receive email at all.
Does it verify that the mailbox actually exists?
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It confirms whether the domain can receive mail via a live MX-record lookup — so it will tell you a domain accepts mail or that a send will bounce — but it doesn't confirm the specific mailbox exists. That requires an SMTP handshake with the receiving server, which Autocloz performs (along with warmup and DMARC/DKIM/SPF monitoring) inside the app.
What is a role-based email address?
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An address whose local part is a function, not a person — info@, sales@, support@, admin@. They're often shared inboxes and tend to convert worse for outreach and be flagged more by filters, so many senders exclude them.
Why avoid disposable email domains?
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Disposable/temporary domains (mailinator.com, yopmail.com, and similar) accept mail briefly then discard it. Sending to them wastes sends, inflates bounce rates and can hurt sender reputation.
Is a free-provider address bad?
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Not inherently — it's expected in B2C. For B2B outreach a personal Gmail/Yahoo address is a weaker signal than a company domain, so it's worth noting, not necessarily excluding.
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Autocloz verifies addresses, warms up mailboxes and monitors DMARC/DKIM/SPF — so more of your list lands. Free, unlimited users.