Email Verification with Live SMTP Proof
Endpoints
Ungrouped Endpoints 5
What is the Email Verification with Live SMTP Proof API?
Live SMTP mailbox checks that say deliverable only with proof. Catch-all, role and opaque providers come back as risky or unknown with a machine-readable reason - no guessing.
Email Verification with Live SMTP Proof API is available on the JoJ API marketplace. Subscribe with a single JoJ API key, call it through one gateway, and pay from one wallet — no separate account or contract with the provider.
Email Verification with Live SMTP Proof API endpoints
- POST
/v1/verifyVerify one address
Same check as GET /v1/verify, with the address in a JSON body ({"email": "..."}). Use it when you prefer not to put addresses in URLs or logs.
- GET
/v1/verifyVerify one address (query string)
Verify a single address with a live SMTP dialogue. Returns a verdict (deliverable / undeliverable / risky / unknown) with a machine-readable reason; mailbox_verified is true only when the mailbox was confirmed by the SMTP check, never by guessing. Pass the address in the email query parameter.
- POST
/v1/verify/batchSubmit a list for verification
Accepts up to 1000 addresses and returns immediately with a job id. Nothing is verified yet: probing is rate-limited per destination mail server on purpose, so a long list takes hours rather than seconds. Poll the job to collect results as they land. Duplicates and blanks are dropped before the job is created, so total may be smaller than what you sent.
- GET
/v1/verify/batch/{id}Collect a batch
Results appear as they are proven, so a running job already carries everything settled so far. A job belongs to the key that created it; another key gets the same 404 as a job that never existed.
- GET
/healthService state
Service health: whether the SMTP probe is enabled and the sizes of the disposable, free-provider and role lists. Free, not billed.
Frequently asked questions about Email Verification with Live SMTP Proof API
Why do I get risky or unknown instead of valid?
Because we only say deliverable when a live SMTP check proved the mailbox exists. Catch-all domains accept every address, and providers such as Outlook and Yahoo never reveal whether a mailbox exists. Instead of guessing, we return risky or unknown with a machine-readable reason, so you can decide how to treat those addresses.
Does the check send an email to the address?
No. The SMTP dialogue stops before any message is transmitted: we ask the recipient's server whether it would accept the address and disconnect. Nothing lands in the inbox.
How is the batch endpoint billed?
One verification per address in the submitted list. Fetching batch results and the health endpoint are free.