Deliverability

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 provided	Credits charged
`email` only	1
`email` + `phone`	3

Request body

{
  "email": "hello@datalinkapis.com",
  "phone": "+447700900123"
}

Field	Type	Required	Description
`email`	string	Yes	The email address to check
`phone`	string	No	Phone number in E.164 format — adds phone HLR check (+2 credits)

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" }'

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
}

Response fields

Field	Type	Description
`email`	string	The address that was checked
`deliverable`	boolean	Whether the address is likely to accept mail
`confidence`	string	Confidence level: `high`, `medium`, or `low`
`syntax_valid`	boolean	RFC 5321 syntax check
`mx_found`	boolean	Whether a valid MX record exists
`smtp_valid`	boolean	Whether the extended SMTP handshake succeeded
`spam_trap`	boolean	Whether the address matches a known spam trap
`disposable`	boolean	Whether the domain is a disposable provider
`catch_all`	boolean	Whether the domain accepts all addresses regardless of existence
`role_account`	boolean	Whether this is a role address (info@, support@, etc.)
`free_provider`	boolean	Whether this is a free consumer email provider
`domain`	string	Domain portion of the address
`credits_used`	integer	Credits deducted — 1 (email only) or 3 (email + phone)

When to use vs `/v1/email`

	`/v1/email` (1cr)	`/v1/deliverability` (up to 3cr)
Syntax check	✓	✓
MX lookup	✓	✓
SMTP check	Basic	Extended 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.

Overview

Core Endpoints

Bundle Endpoints

Endpoint

Request body

Example request

Response

Response fields

When to use vs `/v1/email`

​Endpoint

​Request body

​Example request

​Response

​Response fields

​When to use vs /v1/email

Endpoint

Request body

Example request

Response

Response fields

When to use vs `/v1/email`