Check if an email exists, free
To verify an email address, check its shape and domain, then ask its mail server whether the mailbox exists and hang up before anything is sent. Paste an address and ZapBounce does all of it for you, free and with no signup.
Free, with no signup and no card. Single checks are rate-limited per visitor, and a free account adds 100 credits a month for whole lists.
The first lines appear as you type and never leave your tab. The mailbox answer comes from our own SMTP check when you press Verify email.
How to verify an email address, step by step (free)
These five steps are what every serious email verifier runs. You can do the first two by hand. The third needs port 25, which home connections and browsers keep closed, so the tool above runs it from our side.
Check the address shape
Look for one @, a domain with a dot and no spaces. A bad shape ends the question. A good shape only proves the address is well formed, so
jen@gmial.comstill passes this step.Look up the domain's MX record
The MX record names the server that takes mail for the domain. No MX record and no fallback A record means nothing can be delivered there. You can see it for any domain with our MX lookup.
Ask the mail server about the mailbox
Open an SMTP session on port 25 and send
RCPT TOwith the address. A 250 reply means the server takes mail for it. A 550 means no such user. Hang up beforeDATA, so no message is ever sent.Test for a catch-all domain
Ask the same server about a random address that can't exist. If it says 250 again, the domain accepts everything, and the honest label is catch-all, not valid.
Flag disposable and role addresses
Match the domain against a list of throwaway providers and the part before the @ against role names like
infoandsales. Both can be real mailboxes. They tell you how to use the address, not whether it exists.
The whole check takes a few seconds per address, and no step sends a message. If you'd like the protocol detail, how ZapBounce verifies an email walks through each SMTP reply code, and does verification send an email? covers the question buyers ask most.
What each line of the result means
| Check | What it establishes | What to do next |
|---|---|---|
| Syntax | The address has one @, a domain with a dot in it and no spaces, so a mail server could parse it. | A well-formed typo still has a good shape, as jen@gmial.com shows. The mailbox check asks the mail server, so an address that does not exist comes back invalid. |
| Disposable | The domain matches a known throwaway provider. | Block these at your signup form. The mailbox check sets a disposable flag on every result from its full list. |
| Role address | The part before the @ is a function such as info, billing or support. A +tag is ignored first, so sales+eu@ still counts. | Decide by use: keep role inboxes for support mail, and send them as their own segment for marketing. |
| Provider | The domain is consumer webmail. Yahoo and AOL get a note, because those servers accept every address. | For a company domain, look up its MX records to see who runs the mail. |
| Mailbox | The receiving server's own answer at RCPT TO, read as valid, invalid, catch-all or unknown. | Send to valid, remove invalid, segment catch-all, and re-check unknown later. |
The four results the ZapBounce API returns
The same four results come back from this page, from a bulk upload and from the API.
valid
Valid
The mailbox accepted the address at the SMTP step.
invalid
Invalid
The server rejected the address outright.
catch_all
Catch-all
The domain accepts every address, so the mailbox cannot be confirmed.
unknown
Unknown
The server would not give a straight answer. We say so, and we do not bill it.
Unknown is a result here, not a footnote, and it's never billed. A verifier that hides what it could not resolve is reporting a number about the easy addresses only. Read can catch-all emails be verified? for why catch-all gets its own label too.
Verify a whole list from a CSV
One address at a time suits a signup that looks odd or a contact copied from a business card. For a list, upload a CSV, TXT or XLSX file to the bulk email verifier. You get back your original columns plus the result, the reason and the three flags for every row.
The check is ours, not a wrapper around another vendor's API. Every account gets 100 free credits a month with no card, paid credits never expire, and a result that comes back unknown isn't billed. Duplicates in a file aren't billed either, so a messy export costs what its distinct addresses cost. See pricing for every tier, or verify addresses as they arrive with the real-time API.
Questions
How do I check if an email address exists without sending an email?
Ask the domain's mail server. Look up its MX record, open an SMTP session on port 25, send RCPT TO with the address and read the reply: 250 means it exists, 550 means it does not. Then close the session before DATA. ZapBounce's free email verifier runs these steps for you in a few seconds.
Does verifying an email address notify the person?
No. The check closes the connection before DATA, the step where a message body would start. Nothing reaches the inbox, and the mailbox owner sees nothing.
How do I verify emails in bulk from a CSV for free?
Sign up for ZapBounce and upload the CSV to the bulk verifier. Every account gets 100 free credits a month with no card, duplicates are removed before counting, and an unknown result costs nothing. Larger lists start at $5 for 1,000 checks, and credits never expire.
Is a role address like info@ a bad address?
No, just a different kind. Shared inboxes draw more complaints on marketing sends and are often exactly right for support mail. ZapBounce labels a role address with its own flag and leaves the choice to you.
Why does a verified email still bounce sometimes?
A mailbox can close after the check, fill up, or sit on a catch-all domain that said yes to every address. That is why ZapBounce reports catch-all as its own result instead of folding it into valid. Re-check a list that has sat for more than a few months before you send.
Verify your list free
100 free credits a month, no card, and unknowns are never billed.