final project (alpha)

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Net.Mail;
using System.Net;
using System.Runtime.InteropServices;

namespace FinalProject
{
    public partial class EmailClient : Form
    {
        public EmailClient()
        {
            InitializeComponent();
        }

        private void txtMail_Enter(object sender, EventArgs e)
        {
            if (txtMail.Text == "Кому") {
                txtMail.Clear();
                txtMail.ForeColor = Color.FromArgb(83, 179, 233);
            }
        }

        private void txtMail_Leave(object sender, EventArgs e)
        {
            if (txtMail.Text == "") {
                txtMail.ForeColor = Color.FromArgb(200, 200, 200);
                txtMail.Text = "Кому";
            }
        }

        private void txtSub_Enter(object sender, EventArgs e)
        {
            if (txtMail.Text == "Тема")
            {
                txtMail.Clear();
                txtMail.ForeColor = Color.FromArgb(83, 179, 233);
            }
        }

        private void txtSub_Leave(object sender, EventArgs e)
        {
            if (txtMail.Text == "")
            {
                txtMail.ForeColor = Color.FromArgb(200, 200, 200);
                txtMail.Text = "Тема";
            }
        }

        private void txtMess_Enter(object sender, EventArgs e)
        {
            if (txtMail.Text == "Текст")
            {
                txtMail.Clear();
                txtMail.ForeColor = Color.FromArgb(83, 179, 233);
            }
        }

        private void txtMess_Leave(object sender, EventArgs e)
        {
            if (txtMail.Text == "")
            {
                txtMail.ForeColor = Color.FromArgb(200, 200, 200);
                txtMail.Text = "Текст";
            }
        }

        private void btnSend_Click(object sender, EventArgs e)
        {
            if (txtMail.Text == "" || txtMail.Text == "Кому" || txtSub.Text == "" || txtSub.Text == "Тема") {

                MessageBox.Show("Пожалуйста, введите почту получателя и заголовок темы", "Сообщение не отправлено", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
            else {

                string from, to, password, messageBody;
                MailMessage message = new MailMessage();
                from = "obechekopm@gmail.com";
                to = txtMail.Text;
                password = "LycanMidas3002";
                messageBody = txtMess.Text;
                message.To.Add(to);
                message.From = new MailAddress(from);
                message.Body = "<br>Текст сообщения: " + messageBody;
                message.Subject = txtSub.Text;
                message.IsBodyHtml = true;
                SmtpClient smtp = new SmtpClient("smtp.gmail.com");
                smtp.EnableSsl = true;
                smtp.Port = 587;
                smtp.DeliveryMethod = SmtpDeliveryMethod.Network;
                smtp.Credentials = new NetworkCredential(from, password);

                try
                {

                    smtp.Send(message);
                    DialogResult code = MessageBox.Show("Письмо успешно отправлено", "Письмо отправлено", MessageBoxButtons.OK, MessageBoxIcon.Information);

                    if (code == DialogResult.OK)
                    {

                        txtMail.Clear();
                        txtSub.Clear();
                        txtMess.Clear();
                    }

                }
                catch (Exception ex)
                {

                    MessageBox.Show(ex.Message);
                }

            }
        }
    }
}