Validate a single email address

API at a glance

⚠️
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Please get in touch with your CSM or email [email protected] to enable access.

Description: This API checks if an individual email address is valid, risky, disposable, or role-based. It helps you improve deliverability by validating emails before sending campaigns.

Validation logic & best practices

What it checks:

Mailbox detection
Syntax validation (RFC-compliant)
DNS and MX record lookup
Domain spell checks
ESP-specific formatting (if applicable)

When to use this API:

Use this API to validate email addresses collected directly from:

Newsletter signups
Account registration forms
Checkout or lead capture forms

This helps reduce bounce rates, protect the sender's reputation, and improve deliverability.

Acceptable use:

To ensure compliance, do not use this API to:

Validate emails without the user's consent (no opt-in)
Verify emails from third-party sources (e.g., purchased or rented lists)
Generate, guess, or harvest unknown email addresses

Only use the API with consented, first-party data.

Things to know before you start

This endpoint supports only one email address per request.
The API returns details such as:
- Whether the email is valid
- If it belongs to a disposable or role-based service
- The risk level associated with the address
The maximum request rate may be limited based on account settings.

Request parameters

Check out the request parameters

Email validation parameters

Note: This API supports only one parameter.

Parameter	Type	Required	Description
`email`	`string`	✅ Yes	The email address to validate. Example: `[email protected]` (Maximum: 512 characters)

Example requests & responses

Request example

curl --request GET \
     --url 'https://api.getblueshift.com/api/v1/emails/validate?email=janedoe%40acme.com' \
     --header 'accept: application/json' \
     --header 'authorization: Basic YWNlZDZlNGYxMWExYWVhOTZmNTJkNDg4M2ZmMjI4Mjg6'

Response example

{
  "result": {
    "address": "[email protected]",
    "engagement": {
      "engaging": true,
      "is_bot": false
    },
    "is_disposable_address": false,
    "is_role_address": false,
    "reason": [],
    "result": "deliverable",
    "risk": "low"
  }
}

API error responses

Status code	Description	Example response
400 Bad Request	Missing or invalid email address.	`{ "errors": { "email": ["can't be blank or is invalid"] } }`
401 Unauthorized	API authentication failed due to an invalid or missing API key.	`{ "message": "Not authorized" }`
403 Forbidden	The API key does not have sufficient permissions.	`{ "message": "Permission denied" }`
404 Not Found	The requested API endpoint does not exist.	`{ "message": "Endpoint not found" }`
429 Too Many Requests	The request limit has been exceeded.	`{ "message": "Rate limit exceeded" }`
500 Internal Server Error	An unexpected server error occurred.	`{ "message": "Internal Server Error - Please contact support for more information." }`
502 Bad Gateway	The server received an invalid response.	`{ "message": "Bad Gateway - Please retry the request." }`
503 Service Unavailable	The service is temporarily unavailable.	`{ "message": "Service Unavailable - Try again later." }`
504 Gateway Timeout	The server took too long to respond.	`{ "message": "Gateway Timeout - Retry with exponential backoff." }`

Field reference

Response fields

Field	Type	Description
`address`	string	The email address being verified.
`did_you_mean`	string	Suggestion for typos in the domain (if any).
`is_disposable_address`	boolean	`true` if the domain is disposable.
`is_role_address`	boolean	`true` if the address is role-based (e.g., `admin@`, `sales@`).
`reason`	array	List of reasons why the address may be invalid or risky.
`result`	string	One of: `deliverable`, `undeliverable`, `do_not_send`, `catch_all`, `unknown`.
`risk`	string	Risk level: `low`, `medium`, `high`, or `unknown`.
`root_address`	string	If the input is an alias, this shows the root address.
`engagement.engaging`	boolean	Indicates if the user shows engagement signals.
`engagement.is_bot`	boolean	`true` if the address is likely bot-generated.

Reason codes

Reason	Description
`unknown_provider`	MX provider is not recognized.
`no_mx`	No MX records found for the domain.
`high_risk_domain`	Domain is flagged as high risk.
`subdomain_mailer`	Domain is a subdomain and not whitelisted.
`immature_domain`	Domain is recently created.
`tld_risk`	Top-level domain is considered risky.
`mailbox_does_not_exist`	Mailbox does not exist.
`mailbox_is_disposable_address`	Disposable email address.
`mailbox_is_role_address`	Role-based email address.
`catch_all`	Domain accepts all addresses (catch-all).
`long_term_disposable`	Long-term disposable address.
`failed custom grammar check`	Failed ESP-specific formatting rules.

Result types

Result	Description
`deliverable`	Valid and expected to receive emails.
`undeliverable`	Invalid and likely to bounce.
`do_not_send`	High-risk — avoid sending to this address.
`catch_all`	Domain accepts all addresses; validity can't be confirmed.
`unknown`	Validity cannot be determined. See `reason` for more info.