Finally problem has been resolved.
Namespace :
using System.Text;
using System.Data;
using System.Configuration;
using System.Net;
protected void Page_Load(object sender, EventArgs e)
{
}
private void SendAcknowledgementMail(string FGPResult)
{
NetworkCredential smtpCreds= new System.Net.NetworkCredential("a@gmail.com","Pass");
objemail.To.Add("Abc@gmail.com");
objemail.From = new MailAddress("Abc@gmail.com");
objemail.Subject = "Test Email Sending";
var message = new StringBuilder();
message.Append(txt_UserName.Text;
objemail.Body = message.ToString();
message.Append(User Name);
}
try
{
System.Net.Mail.SmtpClient objSmtpClient = new SmtpClient("smtp.gmail.com");
objSmtpClient.UseDefaultCredentials = false;
objSmtpClient.EnableSsl = true;
objSmtpClient.Credentials = smtpCreds;
objSmtpClient.Port = 587;
if (!string.IsNullOrEmpty(objSmtpClient.TargetName))
{
objSmtpClient.Send(objemail);
lbl_msg.Text = "* Email Send ." ;
}
}