Cloud Outbound Mailer Overview
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Cloud Outbound Mailer Overview

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The Cloud Outbound Mailer API is provided in RESTful form. It is done through the HTTP method GET/POST/DELETE method call.
With this API, you can configure and manage address books, make a request to send emails and check results, and view logs of sending emails.

Common settings

Cloud Outbound Mailer API URL


Request headers

Header Description
x-ncp-apigw-timestamp This is the time elapsed since January 1, 1970 00:00:00 UTC in milliseconds.
If the time differs from that of the API Gateway server by 5 minutes or more, then the request is considered invalid.
x-ncp-iam-access-key This is the Access Key ID value issued by the Naver Cloud Platform portal.
x-ncp-iam-access-key:{Account Access Key}
x-ncp-apigw-signature-v2 This is the signature encrypted Access Key ID value and Secret Key.
x-ncp-apigw-signature-v2:{API Gateway Signature}
x-ncp-lang A value to handle API response value in multiple languages. (Example of input values: ko-KR, en-US, and zh-CN / Default: en-US)
x-ncp-lang:{language code}

Authentication header

The Cloud Outbound Mailer API is provided via Naver Cloud Platform’s API Gateway, which requires you to get two authentication keys (Access Key ID and Secret Key).

For more information, refer to Naver Cloud Platform API Guide.

  • Create authentication key
    • Go to My Page > Manage Account > Manage Authentication Key on the Naver Cloud Platform portal, and then click Create a new API authentication key to create an Access Key ID and Secret Key
    • You can use your existing Access Key ID and Secret Key.

Request example

curl -i -s -X POST \
 -H "Content-Type:application/json" \
 -H "x-ncp-apigw-timestamp:1521787414578" \
 -H "x-ncp-iam-access-key:6uxz1nKkcYwUjWRG5Q1V7NsW0i5jErlu2NjBXXgy" \
 -H "x-ncp-apigw-signature-v2:iJFK773KH0WwQ79PasqJ+ZGixtpDQ/abS57WGQdld2M=" \
 -d '{"senderAddress":"","title":"Hello, ${customer_name}. ","body":"Your grade has been changed from ${BEFORE_GRADE} to ${AFTER_GRADE}.","recipients":[{"address":"","name":"Gildong Hong","type":"R","parameters":{"customer_name":"Gildong Hong","BEFORE_GRADE":"SILVER","AFTER_GRADE":"GOLD"}},{"address":"","name":null,"type":"R","parameters":{"customer_name":"Cheolsu","BEFORE_GRADE":"BRONZE","AFTER_GRADE":"SILVER"}}],"individual":true,"advertising":false}'
  • Create a signature (Add a new line with \n.)

    • Create a StringToSign appropriate for your request, encrypt it with your secret key and the HMACSHA256 algorithm, and encode it with Base64.
    • This value is used as x-ncp-apigw-signature-v2.
  • Sample code

public String makeSignature() {
    String space = " ";  // Space
    String newLine = "\n";  // Line break
    String method = "POST";  // HTTP method
    String url = "/api/v1/mails";  // Full URL under "/" (including query strings), excluding the domain
    String timestamp = "{timestamp}";  // Current timestamp (epoch, millisecond)
    String accessKey = "{accessKey}";  // access key id (from portal or Sub Account)
    String secretKey = "{secretKey}";  // secret key (from portal or Sub Account)

    String message = new StringBuilder()

    SecretKeySpec signingKey = new SecretKeySpec(secretKey.getBytes("UTF-8"), "HmacSHA256");
    Mac mac = Mac.getInstance("HmacSHA256");

    byte[] rawHmac = mac.doFinal(message.getBytes("UTF-8"));
    String encodeBase64String = Base64.encodeBase64String(rawHmac);

  return encodeBase64String;

function makeSignature() {
    $space = " ";  // Space
    $newLine = "\n";  // Line break
    $method = "POST";  // HTTP method
    $uri= "/api/v1/mails";  // Full URL under "/" (including query strings), excluding the domain
    $timestamp = "{timestamp}";  // Current timestamp (epoch, millisecond)
    $accessKey = "{accessKey}";  // access key id (from portal or Sub Account)
    $secretKey = "{secretKey}";  // secret key (from portal or Sub Account)
    $hmac = $method.$space.$uri.$newLine.$timestamp.$newLine.$accessKey;
    $signautue = base64_encode(hash_hmac('sha256', $hmac, $secretKey,true));
    return $signautue;

Common response

Returned as HTTP status code in the response body.

HTTP Status Code Return code Description
200 - Success for usual requests
201 - Resource successfully created
400 77101 Error in login information
400 77102 BAD_REQUEST
400 77103 Resource not found
403 77201 No permission
403 77202 No request to subscribe the email product
500 77301 Default project not found
500 77302 Error in working with external system API


Send emails

Manage recipient groups

Manage template

Manage project config

Manage send block list and unsubscribers

Manage file

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