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Endpoint

POST /v1/deliverability
Cost: 1–3 credits per request (dynamic) Built for email senders who need to protect their sender reputation. Use Deliverability when a bounce or spam trap hit has real consequences — cold outreach campaigns, transactional flows, or any send where deliverability SLAs matter. It goes further than standard email validation by running an extended SMTP handshake and catch-all detection, giving you a confidence rating you can act on before you send. This is a deeper version of the standard email validation. Where /v1/email confirms basic reachability, /v1/deliverability runs an extended SMTP handshake, cross-references known spam trap databases, and applies additional disposable provider detection. Adding a phone field extends the check to include phone HLR.
Fields providedCredits charged
email only1
email + phone3

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Request body

{
  "email": "hello@datalinkapis.com",
  "phone": "+447700900123"
}
FieldTypeRequiredDescription
emailstringYesThe email address to check
phonestringNoPhone number in E.164 format — adds phone HLR check (+2 credits)

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Example request

curl -X POST https://api.datalinkapis.com/v1/deliverability \
  -H "Authorization: Bearer dl_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "email": "hello@datalinkapis.com" }'

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Response

{
  "email": "hello@datalinkapis.com",
  "deliverable": true,
  "confidence": "high",
  "syntax_valid": true,
  "mx_found": true,
  "smtp_valid": true,
  "spam_trap": false,
  "disposable": false,
  "catch_all": false,
  "role_account": false,
  "free_provider": false,
  "domain": "datalinkapis.com",
  "credits_used": 3
}

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Response fields

FieldTypeDescription
emailstringThe address that was checked
deliverablebooleanWhether the address is likely to accept mail
confidencestringConfidence level: high, medium, or low
syntax_validbooleanRFC 5321 syntax check
mx_foundbooleanWhether a valid MX record exists
smtp_validbooleanWhether the extended SMTP handshake succeeded
spam_trapbooleanWhether the address matches a known spam trap
disposablebooleanWhether the domain is a disposable provider
catch_allbooleanWhether the domain accepts all addresses regardless of existence
role_accountbooleanWhether this is a role address (info@, support@, etc.)
free_providerbooleanWhether this is a free consumer email provider
domainstringDomain portion of the address
credits_usedintegerCredits deducted — 1 (email only) or 3 (email + phone)

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When to use vs /v1/email

/v1/email (1cr)/v1/deliverability (up to 3cr)
Syntax check✓✓
MX lookup✓✓
SMTP checkBasicExtended handshake
Spam trap detection—✓
Catch-all detection—✓
Confidence score—✓
Use /v1/deliverability when sending to a list where a bounce or spam trap hit would have significant consequences — e.g. cold outreach or transactional flows with strict deliverability SLAs.