C＃SmtpClient谷歌邮件垃圾邮件文件夹

Question

I send a simple email but it gets into googlemails spam folder. This is not the case for other e-mail accounts. Any ideas?

   MailMessage Email = new MailMessage();
   Email.SubjectEncoding = Encoding.UTF8;
   Email.BodyEncoding = Encoding.UTF8;
   Email.From = new MailAddress(appSettings.MailSender);
   Email.To.Add(empfaenger);
   Email.Subject = "mytitle";
   Email.Body = "Plaintext";
   Email.IsBodyHtml = false;

   SmtpClient MailClient = new SmtpClient(appSettings.MailServer,25);
   MailClient.Timeout = 300000;
   MailClient.EnableSsl = true;
   MailClient.Credentials = new System.Net.NetworkCredential(appSettings.MailUser, appSettings.MailPass);
   MailClient.SendAsync(Email, null);

Answer 1

原来，互联网提供商阻止了邮件服务器。