The bulk email verifier that catches hard bounces before you send.
Upload an email list or check a single address. LeadVector resolves the domain’s mail records, detects the provider and any secure gateway in front of it, and performs a direct SMTP handshake. You get a deliverability status you can act on, not a guess.
Data
/
Email Verifier
Bulk verify
Status
emily@lumenanalytics.com
Valid
d.okafor@fieldstone.io
Catch-all
hello@oldstartup.com
Invalid
sam@northgatecorp.com
Unknown
Results are cached on the contact for 30 days.
How it works
1
Paste an address or upload a file
Single checks in the app, or thousands through a bulk job.
2
We resolve DNS, then talk to the server
MX, A, AAAA, CNAME, and NS records, syntax, disposable domains, then a direct SMTP handshake.
3
Get a status you can act on
Valid, invalid, catch-all, or unknown, with the provider and the MX record behind it.
Real mail-server checks, not a guess.
LeadVector’s own verification engine talks to the receiving server and interprets the response. It recognises the gateways that sit in front of corporate mail and adjusts.
Direct SMTP handshakes with provider-tuned timeouts
Detects Proofpoint, Mimecast, Cisco, Barracuda, Microsoft EOP, and Google Workspace
Tracks catch-all likelihood per domain
emily@lumenanalytics.com
Status
Valid
Mail provider
Google Workspace
Secure gateway
None detected
Catch-all likelihood
Low
MX record
aspmx.l.google.com
Four statuses, one meaning each
Valid
The server accepted the address.
Catch-all
The domain accepts everything, so the address cannot be confirmed.
Invalid
The server rejected the address or the domain has no mail.
Unknown
The server did not give a conclusive answer.
Cached, so you never pay twice.
Results are stored on the contact for 30 days. Disposable and flagged domains are rejected before any check runs.
30-day cache on every verified address
Disposable domains rejected up front
Same statuses in the app, the API, and bulk jobs
Email list verification in bulk.
Hard bounces are what damage a sending domain. Run a list through the email verifier before the first campaign and every address comes back as valid, catch-all, or invalid, with the invalid ones removed before they can bounce. Upload a CSV or XLSX, map the email column, and export the clean list, or verify during a campaign import so nothing unverified reaches a sequence.
Every address checked against DNS and the live mail server
Catch-all domains flagged separately from invalid ones
Results cached for 30 days, so re-checks are free
Works on a single address, a spreadsheet, or a campaign import
List verification
q3-prospects.csv
Checked
4,120
Valid
3,611
Catch-all
318
Invalid
191 · removed before send
Hard bounces avoided
191
Verify addresses from your own code.
Send an email address to the Email Verifier endpoint with your access key. LeadVector checks DNS, the MX record, and the mail server, and returns the status as JSON, drawn from the same credits as the app.
status: the verification result, such as valid, invalid, or catch-all
mxFound and mxRecord: whether the domain accepts mail, and where
email: the address you sent
POST /v1/verify-email
cURL
curl -X POST https://api.leadvector.app/v1/verify-email \ -H "x-api-key: $LEADVECTOR_API_KEY" \ -H "Content-Type: application/json" \ -d '{ "email": "emily@lumenanalytics.com" }'
Response · 200 OK
{ "success": true, "message": "EMAIL_VERIFIED", "data": { "email": "emily@lumenanalytics.com", "status": "valid", "mxFound": true, "mxRecord": "aspmx.l.google.com", "provider": "leadvector" } }
Questions
Common questions about verification.
What does each status mean?
Valid means the server accepted the address. Invalid means it was rejected or the domain has no mail. Catch-all means the domain accepts any address. Unknown means the server did not answer conclusively.
How long are results kept?
Verification results are cached on the contact for 30 days, so re-checking the same address inside that window is free.
Does it work behind Proofpoint or Mimecast?
Yes. LeadVector detects common secure email gateways and interprets their responses rather than treating them as failures.
What is a hard bounce, and why does it matter?
A hard bounce is an email rejected because the address does not exist. Mail providers count bounces against your domain, and a high bounce rate lands the rest of your sending in spam. Verifying a list first removes those addresses before they can bounce.
What does catch-all mean?
A catch-all domain accepts mail for any address, so the server cannot confirm whether a specific mailbox exists. LeadVector flags these separately so you can decide whether to send, rather than marking them valid or invalid.
How many emails can I verify at once?
Whole spreadsheets through Bulk Search: upload a CSV or XLSX, map the email column, and export the results. Single checks run in the app, and every check is available through the API and the CLI.