如何解决Marketo错误：711：电子邮件的文件夹类型无效

Question

我正在尝试使用Marketo的API发送电子邮件。我正在关注this教程并收到一条我无法理解的错误：{"requestId":"0000000000","success":false,"errors":[{"code":"711","message":"Invalid folder type for email"}]}

这是什么意思？我已经创建了一个文件夹，然后在这个文件夹中，我创建了一个程序，然后在这个程序中我创建了这个电子邮件。没有程序我就无法创建一个电子邮件 - 据我所知 - 所以我有点迷失。

由于

编辑：添加我的请求：

我正在用php构建我的请求：

<?php
    $email = new CreateEmail();
    $email->name = "MyEmailName";
    $email->folder = new stdClass();
    $email->folder->id = 3211;
    $email->folder->type = "Folder";
    $email->template = 0003;
    $email->subject = "This email was created with an api call";
    print_r($email->postData());

    class CreateEmail{
        private $host = "mydetails";
        private $clientId = "mydetails";
        private $clientSecret = "mydetails";
        public $name;//name of new email, required - NOCEmai
        public $folder;//json object with two members, id and type(Folder or Program), required
        public $template;//id of parent template
        public $description;//optional description of new 
        public $subject;//subject line of new email
        public $fromName;//from name of new email
        public $fromEmail;//from email of new email
        public $replyEmail;//reply to address of new email
        public $operational;//boolean operational status of email

        public function postData(){
            $url = $this->host . "/rest/asset/v1/emails.json?access_token=" . $this->getToken();
            $ch = curl_init($url);
            $requestBody = $this->bodyBuilder();
            curl_setopt($ch,  CURLOPT_RETURNTRANSFER, 1);
            curl_setopt($ch, CURLOPT_HTTPHEADER, array('accept: application/json'));
            curl_setopt($ch, CURLOPT_POST, 1);
            curl_setopt($ch, CURLOPT_POSTFIELDS, $requestBody);
            curl_getinfo($ch);
            $response = curl_exec($ch);
            return $response;
        }

        private function getToken(){
            $ch = curl_init($this->host . "/identity/oauth/token?grant_type=client_credentials&client_id=" . $this->clientId . "&client_secret=" . $this->clientSecret);
            curl_setopt($ch,  CURLOPT_RETURNTRANSFER, 1);
            curl_setopt($ch, CURLOPT_HTTPHEADER, array('accept: application/json',));
            $response = json_decode(curl_exec($ch));
            curl_close($ch);
            $token = $response->access_token;
            return $token;
        }
        private function bodyBuilder(){
            $requestBody = "&name=" . $this->name . "&folder=" . json_encode($this->folder) . "&template=" . $this->template;
            if (isset($this->description)){
                $requestBody .= "&description=" . $this->description;
            }
            if (isset($this->subject)){
                $requestBody .= "&subject=" . $this->subject;
            }
            if (isset($this->fromName)){
                $requestBody .= "&fromName=" . $this->fromName;
            }
            if (isset($this->fromEmail)){
                $requestBody .= "&fromEmail=" . $this->fromEmail;
            }
            if (isset($this->replyEmail)){
                $requestBody .= "&replyEmail" . $this->replyEmail;
            }
            if (isset($this->operational)){
                $requestBody .= "&operational=" . $this->operational;
            }
            return $requestBody;
        }   
    }