sending mail with attachment in windows

 How to send a mail with attachment from windows form using C#.Net. || Send an Email using corporate or business email address in C#.Net.
To implement the Email Sending in Windows Application  you need to follow the below steps :

Step1 :
On the File menu, click New Project. Select Windows Forms Application as your project type.
Design the Form using controls from Toolbox.

Step2:
Now open the Form.cs page and write the following source code.

Form.cs Code :

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


namespace Sample
{
    public partial class Sample_MailSend : Form
    {

        public AmirAds_MailSend()
        {
            InitializeComponent();
        }
 
        private void Cancel()
        {
            txtFromMail.Text = string.Empty;
            txtMailPassword.Text = string.Empty;
            txtToMail.Text = string.Empty;
            txtCC.Text = string.Empty;
            txtSubject.Text = string.Empty;
            txtAttachments.Text = string.Empty;
            txtBody.Text = string.Empty;
        }

        private void btnSend_Click(object sender, EventArgs e)
        {
            if (txtFromMail.Text == string.Empty || txtMailPassword.Text == string.Empty || txtToMail.Text == string.Empty || txtSubject.Text == string.Empty)
            {
                MessageBox.Show("Please fill all the fields.", "Alert!!");
            }

            else
            {
                string pattern = null;
                pattern = "^([0-9a-zA-Z]([-\\.\\w]*[0-9a-zA-Z])*@([0-9a-zA-Z][-\\w]*[0-9a-zA-Z]\\.)+[a-zA-Z]{2,9})$";

                if (Regex.IsMatch(txtFromMail.Text, pattern) || Regex.IsMatch(txtToMail.Text, pattern) || Regex.IsMatch(txtCC.Text, pattern))
                {
                    System.Net.Mail.MailMessage msg = new System.Net.Mail.MailMessage();
                    msg.From = new MailAddress(txtFromMail.Text);
                    msg.To.Add(txtToMail.Text);//Text Box for To Address

                    if (txtCC.Text != string.Empty)
                    {
                        msg.CC.Add(new MailAddress(txtCC.Text));
                    }

                    msg.Subject = txtSubject.Text; //Text Box for subject
                    msg.IsBodyHtml = true;
                    msg.Body = txtBody.Text;//Text Box for body

                    if (txtAttachments.Text != string.Empty)
                    {
                        System.Net.Mail.Attachment attachment;
                        attachment = new System.Net.Mail.Attachment(txtAttachments.Text);
                        msg.Attachments.Add(attachment);
                    }

                    //msg.Priority = MailPriority.High;
                    System.Net.Mail.SmtpClient client = new System.Net.Mail.SmtpClient("relay-hosting.secureserver.net", 26);
                    client.UseDefaultCredentials = false;
                    client.Credentials = new System.Net.NetworkCredential(txtFromMail.Text, txtMailPassword.Text);
                    client.Port = 26;
                    client.Host = "mail.corporatemail.com ";
                    client.EnableSsl = false;
                    object userstate = msg;
                  
                    try
                    {
                        client.Send(msg);
                        MyMessageBox.ShowBox("Your mail has been sent sucessfully.");
                        this.Close();
                    }
                    catch (Exception ex)
                    {
                        MyMessageBox.ShowBox(ex.Message);
                    }
                    Cancel();
                }
                else
                {
                    MyMessageBox.ShowBox("Invalid email address");
                }
            }
        }
        private void btnCancel_Click(object sender, EventArgs e)
        {
            Cancel();
        }

        private void btnBrowse_Click(object sender, EventArgs e)
        {
            DialogResult res = openFileDialog1.ShowDialog();
            if (res == DialogResult.OK)
            {
                txtAttachments.Text = openFileDialog1.FileName;
            }
        }

       }
}

Step4:
Now build the Solution and Debug it for the output.