Verify email address online with a live SMTP mailbox check in under 2 seconds, so a message you care about does not bounce. Verify email address for free here, and verify as often as you need — 99.9% accuracy, 600 credits a month, plus 20 more every day you log in.
Paste an address and BillionVerify will verify it end to end: syntax, domain, MX records, a live SMTP mailbox probe, disposable providers, and role accounts. Verify email address for free, one verify run, one send decision.
Six layers verify every request, and each one reports separately. Verify email address online in under 2 seconds.
Rejects malformed shapes before the network is touched, so a verify run never wastes SMTP quota on a typo.
Verify that the domain resolves and is configured to receive mail at all.
Verify the mail exchanger records that tell senders where mail for the domain actually goes.
Opens a real session with the receiving server to verify email address online for this exact mailbox.
Flags temporary providers so a verify result can separate deliverable from durable.
Flags shared inboxes like info@ and support@ that verify as deliverable but rarely engage.
Four automated steps verify every address you submit.
The address is cleaned and verified for structure, so a typo fails in milliseconds rather than after a network round trip.
The domain is resolved for MX records. No route means nothing can arrive, and the verify run stops with that reason.
A live SMTP session tests the recipient path. This is the only layer that can verify email address online for real.
Disposable, role, catch-all, and spam-trap signals come back beside the verify verdict rather than folded into it.
<2s
Response Time
Average SMTP verification
99.9%
Accuracy
Multi-layer validation
600
Free Monthly Credits
No signup required
6
Validation Layers
Per address checked
Each tool narrows the verify question to one risk type. Verify email address for free on any of them.
Mailbox-level verification — 20 free SMTP checks per IP / 24h.
Full SMTP verification with clear deliverability status.
Validation steps and tools for cleaner lists.
How to tell if an address is real before you send.
Step-by-step guide with verification best practices.
Bounce prevention
This page exists for one question: if you send, will it arrive? To verify email address online you need evidence from the receiving side, and a verify run gathers that evidence in a fixed order.
Before anything reaches the network, a verify run parses the address and resolves the domain for its MX records. A malformed string or a domain with no mail route cannot receive mail, so those cases end here with a named reason.
Neither layer can verify a mailbox on its own. They only verify that delivery is theoretically possible, which is why a format-only tool consistently over-reports how healthy a list is — it never gets far enough to verify anything real.
To verify email address for free properly, the tool opens a real SMTP session with the receiving server and asks it to verify the recipient path. Nothing is delivered, no confirmation link is sent, and the mailbox owner is never notified that you chose to verify them.
The server's reply is the whole point. An accepted recipient, a permanent rejection, and a temporary deferral are three different facts, and a tool that flattens them is guessing rather than choosing to verify honestly.
Every hard bounce is a small tax on your sending reputation. Mailbox providers watch bounce rates closely, and a campaign sent into a list nobody bothered to verify address by address is the fastest way to end up filtered.
Verify email address online before the send and the bounce simply never happens, because the address was suppressed while it was still cheap to suppress. Verify late and you pay for it in deliverability for weeks.
Disposable providers, role accounts, catch-all domains, and free personal webmail all come back as separate flags. A verify run can mark an address perfectly deliverable and still raise three of them.
Keeping them separate is deliberate: verify email address deliverability with SMTP, then decide audience fit with your own rules. One verify result should not silently make both decisions.
What the answer means
Four states, four actions. The mistake that costs the most is treating anything a verify run left inconclusive as safe.
The recipient path accepted the probe when you ran it. That is as close to a guarantee as the protocol offers, and it is the reason before you verify email address input before a campaign rather than after.
It is still a timestamped observation. Verify email address records again before the next send if the list has been sitting, because nothing about a verify result is permanent.
A permanent failure. The verify run reached the server and the server said no. Sending anyway produces exactly the hard bounce you were trying to avoid.
Keep the row and the reason so the same bad address does not walk back in on the next import from the same source.
A disposable provider or a shared role inbox can accept mail perfectly well, so a verify run marks them deliverable and risky at the same time. Whether that is acceptable depends on why you collected the address.
Verify email address deliverability first, then apply the audience rule. Doing it in the other order throws away good contacts.
Greylisting and provider deferrals are normal. Unknown means the receiving system declined to commit when we tried to verify it, not that the mailbox is bad.
Queue it and verify email address status again later. Most unknowns resolve the second time you verify, because the temporary condition has cleared.
Sending workflow
A verify run is cheapest at the moment the address enters your system and most valuable just before a message leaves it.
Signup, checkout, lead form, profile update. Verify email address input while the person is still on the page, because a typo can only be fixed by the one person who knows the correct answer.
Keep the verify call non-blocking past a short timeout: let the user through as unverified rather than failing the form when a provider is slow, then verify again in the background.
Lists decay. People change jobs, aliases retire, domains migrate. A verify result from last quarter describes a list that no longer exists, so verify again before the campaign.
For a whole file, Bulk Email Verification runs the same engine over every row and returns an export with the reasons preserved.
Invoices, password resets, contract notices, a reply to a hot inbound lead. Verify email address input once and the failure mode disappears.
This page is built for exactly that: verify one address, full SMTP, an answer in about two seconds. Verify email address for free, as often as the work needs.
Limits
The claim is narrow on purpose, which is what makes it reliable. You cannot verify your way to any of the three below.
SMTP acceptance describes the recipient path. Whether the message lands in the inbox depends on your reputation, authentication, content, and complaint history — none of which a verify run can see.
Verify email address deliverability to remove address-level failures, then treat placement as a separate programme with its own metrics.
A deliverable address is not a permitted one. A verify run lowers bounce rate; it does not grant the right to send.
Consent and suppression stay in your own system, applied before you verify rather than after.
An accepting mailbox does not verify the person in your CRM controls it or still works there. A verify run can verify a mailbox and still be pointing at the wrong human.
Verify email address deliverability with SMTP; verify ownership from first-party evidence instead.
Related pages
Every tool here uses one pipeline. The pages differ in the question they are written around — this one is written around when and how to verify.
The Check Email Address page is written around a fast first look at an address rather than a pre-send decision.
Use this page instead when the message is already written and you need when you verify email address online before it goes.
The Email Validator stops at syntax and MX, which makes it a cheap pre-screen but never a deliverability answer.
It cannot verify email address online, and it is careful not to claim that it can.
When one address is not enough, Email List Cleaning keeps deduplication, retries, and reason codes consistent across a whole file.
Verify email address behaviour on a sample here first, then commit credits to the full run. Verify email address for free on the sample.
Paste the address and four steps run: parse the syntax, resolve the domain and its MX records, open a direct SMTP session to verify email address online for that exact mailbox, and attach the risk flags. Results come back in under 2 seconds.
BillionVerify reaches 99.9% accuracy because a verify run does not stop at format. Syntax, DNS, MX, and a live SMTP probe together catch the invalid, inactive, and risky addresses that a format-only tool reports as fine. Verify email address for free and compare the two yourself.
Syntax errors, unregistered domains, missing MX records, mailboxes the server rejects, disposable providers, catch-all domains, and role accounts like info@ and support@. Each comes back with its own reason code, so you can see exactly what the verify run found.
Yes. Upload a CSV to verify email address rows in bulk and download the cleaned file in minutes, or call the real-time API to verify email address online as it arrives from your forms or CRM. Both paths verify with the same engine as this page.
Yes. Verify email address for free with 600 credits a month, plus 20 more every day you log in — no credit card required. The free tier runs the full SMTP probe, so you verify email address for free at the same accuracy paid volume gets.
No. Every verify request runs in real time and the address you verify is never stored. Data is encrypted in transit and deleted immediately after we verify it.
Nineteen free tools alongside the paid AI features, none of them requiring an account.
Email Verify Tools
Check if an email address is valid with a free email verifier, no signup — syntax, MX, SMTP mailbox, disposable, role and catch-all checks.
Recipient evidence — not sender or DNS configuration.
Email Verify Tools
Free email validator for address syntax and published MX records. Run an email syntax and MX check instantly, without claiming SMTP mailbox proof.
Email Verify Tools
Free email spam checker: see whether an address sits on a domain with a recorded spam, phishing, or malware history. Check email for spam risk instantly, no signup.
Email Verify Tools
Free temporary email address detector: spot disposable and throwaway domains in real time, with focused disposable results for signups and list quality.
Email Verify Tools
Free bounce email checker: find out whether an address will hard bounce before you send, with a live SMTP probe. A hard bounce detection tool, no signup.
Email Verify Tools
Email list cleaning service with live SMTP verification on every row: dedupe, suppress hard bounces, keep the reasons. Clean email list free tool, no signup to try.
Verify email address for free — 600 credits a month, plus 20 more every day you log in. A real SMTP probe on every verify, in under 2 seconds.
600 free credits monthly · No signup required · Results in under 2 seconds
