Email 使用邮戳服务设置电子邮件可选预览

我用邮戳发送电子邮件，效果很好。我希望能够设置电子邮件的预览

我使用的代码如下所示：

 var message = new PostmarkMessage()
        {
            To = EmailTo, 
            From = "do-not-reply@test.com",
            TrackOpens = true,
            Subject = Subject, 
            Cc = CcEmail,
            Bcc = bccEmail, 
            TextBody = EmailBody,
            HtmlBody = EmailBody,
            Tag = "test", 
            Headers = new HeaderCollection { new MailHeader("X-CUSTOM-HEADER","Header content") }, 
        };

        var postClient = new PostmarkClient(MainConfig.PostmarkKey);

        try
        {
            return await postClient.SendMessageAsync(message);
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
            return null;
        }

---

我不确定启用预览时缺少了什么。

多亏了邮戳团队，我找到了解决方案