Sending email from windows form application

Sir, the solution to my issue provided by you is not acceptable. Please provide me another solution. Thanks

Yeah Sir my code is ok, even i am giving my code.


using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Net;
using System.Net.Mail;
using System.IO;
using System.Windows.Forms;
using System.Text.RegularExpressions;


namespace ContextMenuStrip
{
public partial class Form1 : Form
{
MailMessage message;
SmtpClient smtp;
public Form1()
{
InitializeComponent();
}

public static bool IsValidEmail(string strEmailAddress)
{
if (strEmailAddress == null)
{
return false;
}
else
{
return System.Text.RegularExpressions.Regex.IsMatch(strEmailAddress, @"^[-a-zA-Z0-9][-.a-zA-Z0-9]*@[-.a-zA-Z0-9]+(\.[-.a-zA-Z0-9]+)*\.(com|edu|info|gov|int|mil|net|org|biz|name|museum|coop|aero|pro|[a-zA-Z]{2})$", RegexOptions.IgnorePatternWhitespace);
}
}

private void exitToolStripMenuItem_Click(object sender, EventArgs e)
{
Application.Exit();
}

private void linkLabel1_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
{
if (openFileDialog1.ShowDialog() != DialogResult.Cancel)
{
label4.Text = openFileDialog1.FileName;
label4.Visible = true;
linkLabel1.Visible = false;
}
}

private void button1_Click(object sender, EventArgs e)
{
try
{
button1.Enabled = false;
button2.Visible = true;
message = new MailMessage();
if (IsValidEmail(textBox1.Text))
{
message.To.Add(textBox1.Text);
}
if (IsValidEmail(textBox2.Text))
{
message.CC.Add(textBox2.Text);
}
message.Subject = textBox3.Text;
message.From = new MailAddress("mashkoor.niit@gmail.com");
message.Body = textBox4.Text;
if (label4.Text.Length > 0)
{
if (System.IO.File.Exists(label4.Text))
{
message.Attachments.Add(new Attachment(label4.Text));
}
}
smtp = new SmtpClient("smtp.gmail.com");
smtp.Port = 587;
//smtp.UseDefaultCredentials = true;
smtp.EnableSsl = true;
smtp.Credentials = new NetworkCredential("mashkoor.niit@gmail.com","*******");
smtp.SendAsync(message, message.Subject);
//smtp.Send(message);
smtp.SendCompleted += new SendCompletedEventHandler(smtp_SendCompleted);

}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
button2.Visible = false;
button1.Enabled = true;
}
}

void smtp_SendCompleted(object sender, AsyncCompletedEventArgs e)
{
if (e.Cancelled == true)
{
MessageBox.Show("Email sending cancelled!");
}
else if (e.Error != null)
{
MessageBox.Show(e.Error.Message);
}
else
{
MessageBox.Show("Email sent successfully!");
}
button2.Visible = false;
button1.Enabled = true;
}

private void Form1_Load(object sender, EventArgs e)
{
button2.Visible = false;
}

private void button2_Click(object sender, EventArgs e)
{
smtp.SendAsyncCancel();
MessageBox.Show("Email sending cancelled!");
}
}
}