Email verifier that tells you who will actually get the message
Upload a list, or send addresses through the API, and get every one back with a state you can act on. Seven checks per address, catch-all domains handled properly, and no email is ever sent to the person.
Every address on a list decays. People change jobs, companies change domains, and a mail server that accepted everything last year rejects it this year. Send to a list that hasn't been checked and the bounces do more than waste a send: mailbox providers read the bounce rate as a signal about you, and the next campaign lands in spam for everyone, including the good addresses.
An email verifier checks each address before you send, without sending anything to it, and removes the invalid, disposable and risky ones. The part most checkers get wrong is catch-all domains, which accept any address at the handshake and bounce the bad ones later. We treat those as their own state instead of calling them valid.
Three ways to verify
Same checks, same states, whichever way the addresses arrive.
Verify in bulk
Drop a CSV in the dashboard, pick the email column, and download the same file with a state per row. Up to 10,000 addresses per file, as many files as you need, with progress live while it runs.
Verify through the API
Create a verify job with your rows, poll it, fetch the result. Put it in a sign-up form, a CRM workflow or a Clay table so bad addresses never get in.
Verify what you find
Every address the email finder returns has already been through these checks. Use the verifier on lists you got elsewhere, and the finder for people you don't have an address for yet.
What a clean list changes
Fewer bounces
Invalid and disposable addresses leave before the send. Addresses we mark valid bounce under 2% of the time, measured over the last 90 days.
A sender domain that stays healthy
Providers score your domain on every campaign. Keeping bounces low keeps the score where your good messages still reach the inbox.
More messages in the inbox
Spam filters weigh engagement and complaints. Sending only to real, active mailboxes keeps both numbers on your side.
Replies from people who exist
A list half full of dead addresses halves your reply rate before anyone reads a word. Verified lists make the rest of the funnel honest.
The seven checks behind every result
Each address goes through all seven. The outcome is one state, not a score you have to interpret.
| Check | What it looks at | What it catches |
|---|---|---|
| Syntax | Shape of the address against the standard | Typos, missing @, stray spaces, bad characters |
| Disposable and gibberish | Known throwaway providers and random strings | Temporary inboxes, keyboard-mash sign-ups |
| Domain | Whether the domain exists and resolves | Dead companies, misspelled domains |
| MX records | Whether the domain publishes a mail server | Domains that can't receive mail at all |
| Mail server | A connection to the server, without sending | Servers that are down or refusing mail |
| Mailbox | Whether this specific address is accepted | Addresses that no longer exist |
| Catch-all | Whether the domain accepts every address, plus pattern and delivery evidence | Accept-all domains that would read as valid on a basic checker |
Four states, and what to do with each
| State | Meaning | What to do |
|---|---|---|
| Valid | Mailbox confirmed, or delivered recently | Send |
| Catch-all | Domain accepts everything; this address unproven | Send from a warmed domain in small batches, or find a verified address first |
| Invalid | Rejected, malformed, disposable, or no mail server | Drop |
| Unknown | No answer in time, usually greylisting or rate limits | Re-check later |
The CSV you download is your file with the state appended per row, columns and order unchanged.
Who verifies before they send
Before a sequence goes out
A list from an event, a scrape or an old CRM export. Clean it, send to the valid rows, and keep the catch-all rows for a slower, warmer sequence.
Before a newsletter or launch
One send to a stale list can cost a domain months of reputation. Verify the list every quarter and before anything big.
On intake
Clean a client's list the day it arrives, keep the report, and have the bounce conversation before the campaign instead of after.
What a verifier can and cannot promise
Anyone claiming near-perfect accuracy on catch-all domains is counting accepts as valid.
- ✓Tell valid from catch-all with evidence rather than a coin flip
- ✓Catch disposable, gibberish and malformed addresses before they cost a bounce
- ✓Check without sending anything to the address
- ✓Keep your columns and order; only the state column is added
- ✓Re-check unknown rows later
- ×Resolve every catch-all domain; some hide mailbox existence on purpose
- ×Repair a sending domain that is already blacklisted
- ×Replace warm-up and sensible sending volumes on your side
More than a checker
Verification is one step. The rest of the record is next door.
Email verification, answered
What is an email verifier?
A tool that checks whether an email address can receive mail before you send to it. It looks at the address, the domain, the mail server and the mailbox, and returns a state per address so you can keep, hold or drop it.
How does the verification process work?
Seven checks in sequence: syntax, disposable and gibberish detection, domain, MX records, mail server, mailbox, and catch-all. The results combine into one state: valid, catch-all, invalid or unknown.
Do you send an email to the address to verify it?
No. The checks talk to the mail server up to the point where it says whether it would accept the address, then stop. The person never sees anything.
What is a catch-all (accept-all) email address?
An address on a domain whose server accepts any recipient during the handshake, whether or not the mailbox exists, and may bounce it later. A basic checker calls these valid. We label them catch-all and add pattern and delivery evidence to resolve the ones we can.
Can a verified address still bounce?
Rarely. A mailbox can be deleted between the check and the send, and some servers accept at the handshake and bounce later. Addresses we mark valid bounce under 2% of the time over the last 90 days; that figure is measured, not promised.
What is the difference between verification and validation?
Validation checks the format of the address. Verification goes further and checks the domain, the server and the mailbox. Format alone tells you almost nothing about whether a message will land.
What do the states mean?
Valid: send. Catch-all: the domain accepts everything and we couldn't prove this address; send carefully or find a verified one. Invalid: rejected, malformed or disposable; drop it. Unknown: the server didn't answer in time; re-check later.
Can I verify free mailboxes like Gmail or Outlook?
Yes. Consumer providers answer the mailbox check reliably, so those addresses usually come back valid or invalid rather than catch-all.
What is greylisting?
A server tactic that temporarily refuses a first connection and accepts a retry a little later. We retry within a time limit; addresses that still don't answer come back as unknown, and you can re-check them.
How many addresses can I verify at once?
Up to 10,000 per file in the dashboard, and as many files as you like. Through the API, the same limit per job.
How often should I verify a list?
Before any send to a list older than three months, and before anything large. B2B addresses decay at roughly a quarter to a third a year as people change jobs.
Is it included in my plan?
Yes. Verification is paid from the same credits as everything else, on every plan including the free one. The rate and the plans are on the pricing page, and your balance is in the dashboard.
Do you keep the lists I upload?
Your files stay on your account until you delete them so you can re-download results. Uploaded addresses are not added to our database.
Verify the list you were about to send
Free account, no card. Upload, wait a few minutes, download four states.