title: failure sending mail in C# .net
body: <p>My code for sending email was working correctly the psat two weeks. But now it shows an error like </p>
  
  <blockquote>
    <p>Failure Sending Mail.</p>
  </blockquote>
  
  <p>I don't know why this problem has raise. Some new new firewall policies were placed last week, is it because of this the problem is raised? What should I do?</p>
  
  <p>Here is my code:</p>
  
  <pre><code> protected void Button1_Click(object sender, EventArgs e)
      {
          try
          {
              if (TextBox1.Text == "")
              {
  
                  string alertmessage = "";
                  alertmessage = "Email ID. cannot be blank ";
                  this.CreateMessageAlert(this, alertmessage, "alertKey");
                  TextBox1.Focus();
              }
              else if (TextBox2.Text == "")
              {
  
                  string alertmessage = "";
                  alertmessage = "CC To cannot be blank ";
                  this.CreateMessageAlert(this, alertmessage, "alertKey");
                  TextBox2.Focus();
              }
              else if (TextBox3.Text == "")
              {
  
                  string alertmessage = "";
                  alertmessage = "Subject cannot be blank ";
                  this.CreateMessageAlert(this, alertmessage, "alertKey");
                  TextBox3.Focus();
              }
              else if (TextBox4.Text == "")
              {
  
                  string alertmessage = "";
                  alertmessage = "Message Body cannot be blank ";
                  this.CreateMessageAlert(this, alertmessage, "alertKey");
                  TextBox4.Focus();
              }
              //else if (upSignature.FileName == "")
              //{
              //    ctr = 1;
              //    string alertmessage = "";
              //    alertmessage = "Attachment  Missing...";
              //    this.CreateMessageAlert(this, alertmessage, "alertKey");
              //    upSignature.Focus();
              //}
  
              else
              {
  
  
                  string photo = "Enquiry" + Session["MRNO"].ToString() + FileUpload1.FileName;
                  string strpath = Request.MapPath("~/");
                  FileUpload1.SaveAs(strpath + "/Enquiry/" + photo);
  
  
                  try
                  {
                      MailMessage mail = new MailMessage();
                      mail.To.Add(new MailAddress(TextBox1.Text.Trim()));
                      mail.From = new MailAddress("XXXXXXX");
                      mail.Subject = "Enquiry for MRNO " + " " + " " + Session["MRNO"].ToString() + " " + " " + "Reg.";
                      mail.CC.Add(TextBox2.Text.Trim());
                      mail.Body = TextBox4.Text.Trim();
  
                          mail.Attachments.Add(new Attachment(FileUpload1.PostedFile.InputStream, FileUpload1.FileName));
                          mail.Attachments.Add(new Attachment(FileUpload2.PostedFile.InputStream, FileUpload2.FileName));
  
                      //Attachment attach = new Attachment(strpath + "/Enquiry/" + photo);
                      //mail.Attachments.Add(attach);
  
  
                      SmtpClient smtp = new SmtpClient("smtp.gmail.com", 587);
  
                      smtp.EnableSsl = true;
  
                      smtp.UseDefaultCredentials = false;
                      smtp.Credentials = new NetworkCredential("XXXXXX", "XXXXXXX");
  
                      smtp.Send(mail);
  
                      string alertmessage = "";
                      alertmessage = "Mail Has Been Sent";
                      this.CreateMessageAlert(this, alertmessage, "alertKey");
  
  
                      //   Page.RegisterStartupScript("close", "&lt;script language=javascript&gt;self.close();&lt;/script&gt;");
  
                  }
                  catch (Exception ex)
                  {
                      Response.Write(ex.Message);
                  }
              }
          }
          catch (Exception ex1)
          {
              Response.Write(ex1.Message);
          }
  
      }
  </code></pre>