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§ · free tool
Free email verifier. Live DNS, not guesswork.
Paste a list or drop a CSV. Every address is checked against live mail-server records, then scored for syntax, dead domains, disposable providers, role accounts and abuse desks. Your list never leaves the browser.
A free online tool by Digital HeroesAn email verifier checks whether an address can actually receive mail before you send to it. This one runs four passes on every row: RFC syntax, a live MX lookup over DNS-over-HTTPS, a reputation pass for disposable domains, role accounts and abuse-desk traps, and a duplicate pass that collapses Gmail dot and plus aliases. Each address comes back with a status, a risk score out of 100, and a single send decision you can filter on. Nothing is uploaded; only the domain part of your list is ever queried, never the full address.
Up to 500 addresses per run. Results appear as each one resolves.
verdict · live
- No results yet.
Send
0
Risky
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Skip
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Valid means the domain provably accepts mail and the address is clean. Confirming one specific mailbox needs an SMTP probe on port 25, which no browser can open. Any tool claiming otherwise in-browser is guessing.
| Decision | Status | Risk | Address | Why |
|---|---|---|---|---|
| Results will appear here. | ||||
What does each check actually do, and which specification does it follow?
- Syntax. Local part, domain labels and TLD are checked against RFC 5322 shape rules. Internationalised domains are converted to punycode so they resolve.
- MX lookup. Live query to Cloudflare DNS-over-HTTPS, with Google DoH as fallback. No mail exchanger means nothing can receive mail.
- Null MX. A domain publishing a single empty exchanger is declaring under RFC 7505 that it accepts no mail at all. That is a definitive invalid, and most cheap verifiers miss it.
- A-record fallback. Under RFC 5321 section 5.1 a domain with no MX but a valid A record still receives mail. Verifiers that skip this throw away good addresses.
- SPF and DMARC. Absence suggests an unmanaged or abandoned domain. Presence tells you how hard the recipient filters what you send.
- Provider fingerprint. The MX hostnames identify Google Workspace, Microsoft 365, Zoho and security gateways such as Mimecast, Proofpoint and Barracuda.
- Deduplication. Gmail ignores dots and anything after a plus, so one person can appear as five rows. Those collapse to one.
Privacy: addresses are processed in your browser. Only the domain half is sent to Cloudflare or Google DoH for the DNS lookup. Digital Heroes stores nothing and logs nothing.
§ · questions
Email verifier FAQ
Is this email verifier really free?
Yes. There is no signup, no credit system and no paid tier. The tool runs entirely as JavaScript in your browser, so there is no per-address cost to pass on to you. Verify one address or five hundred, as often as you like.
Does my email list get uploaded anywhere?
No. The addresses stay in the browser tab and are never sent to a Digital Heroes server. The only outbound requests are DNS lookups, and those carry the domain part only. Checking jane at acme.com asks the resolver about acme.com; the name jane is never transmitted.
Can it confirm that one specific mailbox exists?
No, and no browser-based tool can. Confirming a single mailbox means opening an SMTP session to the recipient's mail server on port 25 and reading its reply to a RCPT TO command. Browsers cannot open raw TCP sockets, and port 25 is blocked on virtually every consumer connection and cloud host. This tool verifies everything short of that, which removes most of the bad rows in a typical list, and it says plainly when it cannot know.
What is a catch-all domain and why does it matter?
A catch-all domain accepts mail for every possible address, then decides later whether to keep it. An acceptance therefore proves nothing about whether a real person reads that mailbox, and messages often bounce days after you send. Catch-all detection needs the same SMTP probe described above, so treat an address on an unfamiliar domain as unconfirmed until you have sent to it once.
How is this different from the email list cleaner?
The email list cleaner is a hygiene pass. It trims, deduplicates and normalises a messy list without touching the network. This verifier does the deliverability work on top, querying live DNS for every domain to prove that mail can reach it. Clean first, then verify.
Why are some real addresses marked risky rather than valid?
Risky is not a claim that the address is wrong. It flags rows carrying extra sending risk: role accounts such as info or sales that no individual owns, domains with no SPF record, free consumer mailboxes on a business campaign, and duplicates. Those are judgement calls about whether to spend a send, not verdicts on validity.
What bounce rate should I aim for before a campaign?
Keep hard bounces under two percent. Past roughly five percent, mailbox providers begin throttling delivery and your sending reputation degrades for weeks afterwards. Removing every address this tool marks skip, then treating risky rows as a separate lower-volume segment, is usually enough to stay well under that line.
How many addresses can I verify at once?
Five hundred per run. The limit keeps the tool polite to the public DNS resolvers it depends on. Results are cached per domain within a run, so five hundred addresses spread across forty companies costs only forty lookups and finishes in seconds.
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