信箱不可用。服务器响应是：不允许传递到此地址

Question

我最近为我的应用转移了提供商，现在当应用尝试发送邮件时出现以下错误

  

邮箱不可用。服务器响应是：不允许传递到此地址。

我尝试了各种不同的电子邮件地址，以及他们的技术支持，但事实证明这些地址没那么有用。

这是一个asp.net mvc应用程序，控制器代码是：

        public ActionResult EmailEventRegister(int eventId)
    {
        //Find Event
        var eventSel = db.Events.FirstOrDefault(t => t.EventId == eventId);

        MailMessage enteredMessage = new MailMessage();
        enteredMessage.Subject = "YFA Event Attendance Details for " + eventSel.Name + " " + eventSel.EventDate.ToLongDateString();
        enteredMessage.IsBodyHtml = true;
        var bodyBuilder = new StringBuilder();
        bodyBuilder.AppendLine(branch.BranchName + " YFA are attending the following event: " +
              "<br />" +
              "<br />Event: " + eventSel.Name +
              "<br />");

        enteredMessage.Body = bodyBuilder.ToString();
        enteredMessage.From = new MailAddress("phillsanders@me.com", "Droitwich YFA");

        enteredMessage.CC.Add("phillsanders@me.com");

        enteredMessage.To.Add(new MailAddress("phillsanders@me.com"));
        SmtpClient mySmtpClient = new SmtpClient("icebreak.host4asp.net");

        NetworkCredential Credentials = new NetworkCredential("contact@yfainfo.com", "Passwordhere");
        mySmtpClient.Credentials = Credentials;
        mySmtpClient.Send(enteredMessage);

        mySmtpClient.Send(enteredMessage);

        var userId = User.Identity.GetUserId();
        var branchId = db.Instructors.FirstOrDefault(x => x.ApplicationUserId == userId).BranchId;

        return RedirectToAction("Index", "Events", new { branchId = branchId});
    }