Help solving 'System.Net.Mail.SmtpException' in VBE 2013

Hello - I am using VS Express 2013 for Windows Desktop. I am making an app to send email using c#. I am getting the following exception messages when I run my WindowsFormsApplication:

A first chance exception of type 'System.Net.Mail.SmtpException' occurred in System.dll
Additional information: The operation has timed out.

An unhandled exception of type 'System.Net.Mail.SmtpException' occurred in System.dll
Additional information: The operation has timed out.

Here is my code:

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.Web;
using System.Net.Mail;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();

            password.PasswordChar = '*';
        }

        private void textBox2_TextChanged(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {
            MailMessage mail = new MailMessage(from.Text, to.Text, subject.Text, body.Text);
            SmtpClient client = new SmtpClient(smtp.Text);
            client.Port = 465;
            client.Credentials = new System.Net.NetworkCredential(username.Text, password.Text);
            client.EnableSsl = true;
            client.Send(mail);
            MessageBox.Show("Mail Sent", "Success", MessageBoxButtons.OK);
        }

        private void body_TextChanged(object sender, EventArgs e)
        {

        }
    }
}

Can anyone help me find out why the exeptions are occurring and how to fix the problem?

I have been looking for the solution for some time now. I hope sonemone here can give me a hand.

Thanks