Hubspot Marketing Emal Transactional Email Request Structure

{
  "type": "object",
  "description": "Request body for sending a transactional email",
  "name": "TransactionalEmailRequest",
  "properties": {
    "emailId": {
      "type": "integer",
      "description": "The ID of the transactional email template to use"
    },
    "message": {
      "type": "object",
      "description": "The email message configuration",
      "properties": {
        "to": {
          "type": "email",
          "description": "The recipient's email address"
        },
        "from": {
          "type": "email",
          "description": "Override the from address (must be verified)"
        },
        "sendId": {
          "type": "string",
          "description": "A unique ID to prevent duplicate sends"
        },
        "replyTo": {
          "type": "array",
          "description": "Reply-to email addresses",
          "items": {
            "type": "email"
          }
        },
        "cc": {
          "type": "array",
          "description": "CC email addresses",
          "items": {
            "type": "email"
          }
        },
        "bcc": {
          "type": "array",
          "description": "BCC email addresses",
          "items": {
            "type": "email"
          }
        }
      },
      "required": [
        "to"
      ]
    },
    "contactProperties": {
      "type": "object",
      "description": "Properties to set on the contact (if createContact is enabled)"
    },
    "customProperties": {
      "type": "object",
      "description": "Custom template variables for personalization"
    }
  },
  "required": [
    "emailId",
    "message"
  ],
  "$schema": "https://json-structure.org/draft/2020-12/schema"
}