E-Mail Send - Resevie C# Code

using System;
using System.Windows.Forms;
using System.Net.Mail;

namespace WindowsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                MailMessage mail = new MailMessage();
                SmtpClient SmtpServer = new SmtpClient("smtp.gmail.com");

                mail.From = new MailAddress("your_email_address@gmail.com");
                mail.To.Add("to_address@mfc.ae");
                mail.Subject = "Test Mail";
                mail.Body = "This is for testing SMTP mail from GMAIL";

                SmtpServer.Port = 587;
                SmtpServer.Credentials = new System.Net.NetworkCredential("username", "password");
                SmtpServer.EnableSsl = true;

                SmtpServer.Send(mail);
                MessageBox.Show("mail Send");
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }
        }
    }
}

Send Email in C# Code

// create mail message object
MailMessage mail = new MailMessage();
mail.From = "";           // put the from address here
mail.To = "";             // put to address here
mail.Subject = "";        // put subject here 
mail.Body = "";           // put body of email here
SmtpMail.SmtpServer = ""; // put smtp server you will use here 
// and then send the mail
SmtpMail.Send(mail);

==================================================

String server = "127.0.0.1";
 
private void btnSend_Click(object sender, System.EventArgs e)
{
 MailAddress to = new MailAddress("admin@.mail.adr");
 MailAddress from = new MailAddress(txtFrom.Text);
 MailMessage message = new MailMessage(from, to);  
 
 message.Subject = txtSubject.Text;
 message.Body = @"" txtContent.Value;

 SmtpClient client = new SmtpClient(server);
 
 try
 {
 client.Send(message);
  }
 catch (Exception ex)
 {
 throw new Exception(ex.Message, ex);
 }
}

Other Example 

using System;
using System.Text;
using System.Net.Mail;
using System.Net;

namespace TestingConsole
{
  class Program
  {
      static void Main(string[] args)
      {
          try
          {
              string to = "to@domain.com";
              string from = "from@gmail.com";
              string from_pwd = "mypassword";
              string subject = "Sample Mail testing";
              string body = "Wow this is testing body";
              MailMessage mM = new MailMessage();
              mM.From = new MailAddress(from);
              mM.To.Add(to);
              mM.Subject = subject;
              mM.Body = body;
              mM.IsBodyHtml = false;
              mM.Priority = MailPriority.High;
              SmtpClient sC = new SmtpClient("smtp.gmail.com");
              sC.Port = 587;
              sC.Credentials = new NetworkCredential(from,from_pwd);
              sC.EnableSsl = true;
              sC.Send(mM);
          }
          catch (Exception e)
          {
              Console.WriteLine(e.Message + " " + e.StackTrace);
          }
      }
  }
}