ضبط smtp

السلام عليكم ورحمة الله وبركاتة تظهر لة رسالة خطا وهى The SMTP server name is required, and was not found in the configuration source

فكيف يتم ضبط smtp

private void SendMessageToMGOC()

{

SqlConnection sqlCon = new SqlConnection("Data Source=.;Initial Catalog=test1;Integrated Security=True");

sqlCmd = new SqlCommand();

sqlCmd.CommandText = "select emailFrom , emailTo from webmail Where formName='ContactUs'";

sqlCmd.CommandType = CommandType.Text;

sqlCmd.Connection = sqlCon;

sqlCmd.Connection.Open();

SqlDataReader sda = sqlCmd.ExecuteReader();

if (sda.Read())

{

MailTo = sda["emailTo"].ToString();

MailFrom = sda["emailFrom"].ToString();

MailSubject = "ContactUs";

}

else

{

MailTo = "info@mgo-center.com";

MailSubject = "ContactUs";

MailFrom = "Ahmed2210@gmail.com";

}

sda.Close();

sqlCon.Close();

StreamReader SR = File.OpenText(Server.MapPath("ContactUs.aspx"));

MailMessage = SR.ReadToEnd();

MailMessage = MailMessage.Replace("@@Name@@", txtfullname.Text);

MailMessage = MailMessage.Replace("@@Mail@@", txtemail.Text);

MailMessage = MailMessage.Replace("@@Address@@", txtAddress.Text);

MailMessage = MailMessage.Replace("@@Tel@@", txtTel.Text);

MailMessage = MailMessage.Replace("@@Message@@", txtMessage.Text);

MailMessage = MailMessage.Replace("@@ServerName@@", Request.ServerVariables["aessa-it.mohsmc.local"]);

Mail.From = txtemail.Text;

Mail.To = MailTo;

Mail.Subject = MailSubject;

Mail.Body = MailMessage;

//SelectMailSystemInfo();

Mail.Fields["http://schemas.microsoft.com/cdo/configuration/smtsperver"] = SMTP;

Mail.Fields["http://schemas.microsoft.com/cdo/configuration/smtpserverport"] = 26;

//Mail.Fields["http://schemas.microsoft.com/cdo/configuration/sendusing"] = 2;

Mail.Fields["http://schemas.microsoft.com/cdo/configuration/smtpauthenticate"] = 1;

Mail.Fields["http://schemas.microsoft.com/cdo/configuration/sendusername"] = UserName;

Mail.Fields["http://schemas.microsoft.com/cdo/configuration/sendpassword"] = Password;

Mail.BodyFormat = MailFormat.Html;

Mail.BodyEncoding = System.Text.Encoding.UTF8;

System.Web.Mail.SmtpMail.SmtpServer = SMTP;

System.Web.Mail.SmtpMail.Send(Mail);خطا تظهر لة فى هذا سطر بارسالة error الذى فوق

}

}