json_schema: {
      "$schema": "http://json-schema.org/draft-04/schema#",
      "title": "HTML Email Template Schema",
      "description": "Defines the customization points available in an HTML body email template.",
      "type": "object",
      "additionalProperties": false,
      "required": [
          "meta",
          "htmlContent"
      ],
      "properties": {
          "meta": {
              "type": "object",
              "title": "Email",
              "required": [
                  "fromName",
                  "fromAddress",
                  "subject"
              ],
              "additionalProperties": false,
              "properties": {
                  "fromName": {
                      "type": "string",
                      "title": "From Name",
                      "default": "My Company",
                      "propertyOrder": 1,
                      "minLength": 1,
                      "options": {
                          "validate": [
                              "handlebars"
                          ]
                      }
                  },
                  "fromAddress": {
                      "type": "string",
                      "title": "From Address",
                      "default": "company@example.com",
                      "propertyOrder": 2,
                      "minLength": 5,
                      "options": {
                          "validate": [
                              "handlebars"
                          ]
                      }
                  },
                  "subject": {
                      "type": "string",
                      "title": "Subject",
                      "propertyOrder": 3,
                      "minLength": 1,
                      "options": {
                          "validate": [
                              "handlebars"
                          ],
                          "input_height": "50px"
                      }
                  }
              }
          },
          "htmlContent": {
              "type": "string",
              "title": "HTML Content",
              "description": "Raw HTML content that can use {{mergeTags}} from handlebars"
          }
      }
  }