API at a glance

Description: This API allows you to validate multiple email addresses (up to 30 email addresses) in a single request. It helps you identify risky or invalid addresses before launching campaigns at scale.

Validation logic & best practices

Authentication & testing - Email validation

Testing the API on this page

How to try it here

Use your Email Validation Key as the Username (leave Password blank).

Select the appropriate API endpoint based on your Blueshift region.

Enter the necessary parameters and click Try It to run the request.

Authentication using Base64 encoding

Note for developers

API requests require authentication using HTTP Basic Authentication with the Email Validation Key (contact your CSM for this key). The Email Validation Key serves as the username, while the password field should be left empty. The format to encode is: your_api_key: (note the trailing colon).

This string must be Base64-encoded and included in the request's Authorization header as follows:

Authorization: Basic encoded_value

You can generate the encoded value using a trusted Base64 encoder.

Postman collection

Try it with Postman: Explore the API using Blueshift's Postman collection.

Things to know before you start

You can validate up to 30 email addresses per request.
The API returns an array of results with individual validation data.
Requests exceeding 30 emails will return a 413 Payload Too Large error.
The maximum request rate may be limited based on account settings.

Request parameters

Check out the request parameters

Bulk validation parameters

Parameter	Type	Required	Description
`emails`	`string[]`	✅ Yes	An array of email addresses to validate. Example: `["a@x.com", "b@y.com"]` (Maximum: 512 characters)

Example requests & responses

Request example

  curl --request POST \
       --url https://api.getblueshift.com/api/v1/emails/bulk_validate \
       --header 'accept: application/json' \
       --header 'authorization: Basic YWNlZDZlNGYxMWExYWVhOTZmNTJkNDg4M2ZmMjI4Mjg6' \
       --header 'content-type: application/json' \
       --data '
  {
    "emails": [
      "janedoe@acme.com",
      "bob@tempmail.com"
    ]
  }
  '

{
  "result": [
    {
      "janedoe@acme.com": {
        "address": "janedoe@acme.com",
        "engagement": {
          "engaging": true,
          "is_bot": false
        },
        "is_disposable_address": false,
        "is_role_address": false,
        "reason": [],
        "result": "deliverable",
        "risk": "low"
      }
    },
    {
      "bob@tempmail.com": {
        "address": "bob@tempmail.com",
        "engagement": {
          "engaging": false,
          "is_bot": false
        },
        "is_disposable_address": true,
        "is_role_address": false,
        "reason": ["disposable"],
        "result": "invalid",
        "risk": "high"
      }
    }
  ]
}

API error responses

Status code	Description	Example response
400 Bad Request	Missing or malformed payload.	`{ "errors": { "emails": ["must be an array of strings"] } }`
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" }`
413 Payload Too Large	More than 30 email addresses were submitted.	`{ "message": "You can validate a maximum of 30 emails in one API call." }`
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." }`

200Bulk email validation result.

400Bad Request - The request contains missing or invalid parameters.

401Unauthorized - API authentication failed due to an invalid or missing API key.

403Forbidden - The API key does not have sufficient permissions to perform this action.

404Not Found - The requested API endpoint does not exist.

413Payload Too Large - The request payload exceeds the allowed limit.

429Too Many Requests - The request limit has been exceeded.

500Internal Server Error - An unexpected error occurred.

502Bad Gateway - The server received an invalid response.

503Service Unavailable - The service is temporarily unavailable.

504Gateway Timeout - The server took too long to respond.