Sign in
Email Messages

Create a batch of email messages

Creates up to 1,000 email messages in a single request. Request-wide admission checks run first and can reject the whole batch before message creation. After those checks pass, each message is validated and sent independently; item-level failures do not affect other messages, and the processed batch returns 207 Multi-Status.

post/email_messages/batch

Headers

Idempotency-Keystring

Optional opaque, unquoted key for safely retrying the same logical request. Keys must contain 1 to 255 letters, numbers, hyphens, or underscores. Generate a unique UUID v4 for each operation and reuse it only when retrying that operation with the same request. Invalid headers—including duplicate, empty, malformed, or overlong values—return 400 with error code 10015. A request already in progress with the same key returns 409; reusing the key with a different request returns 422. Only successful responses are replayed, for up to 24 hours. Do not include sensitive data in the key.

Request body

sandbox_modeboolean

Applies sandbox mode to all messages in the batch. Overrides any per-message sandbox_mode in the messages array.

Response

Multi-Status — returned after request-wide admission checks pass and item processing runs. When all messages succeed, errors is empty and every item is in data. When one or more items fail, the response contains a data array for successes and an errors array for failures. Request-wide gates can instead return 4xx or 5xx.

Example response

{
  "data": [
    {
      "recipient_statuses": {
        "delivered": 998,
        "bounced": 2
      }
    }
  ]
}

Changes