error while sending email from vb.net 2010

See more:

VB

email

Imports System.Net
Imports System.Net.Mail

Public Class Form1

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        lblDateTime.Text = "Date: " & Date.Today() & " " & "Time: " & TimeOfDay()

    End Sub

    Private Sub btnSend_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSend.Click
        Try
            Dim email As New MailMessage()
            Dim smtp As New SmtpClient()

            smtp.UseDefaultCredentials = False
            smtp.Credentials = New Net.NetworkCredential(txtUsername.Text, txtPassword.Text)
            smtp.Port = 465
            smtp.EnableSsl = True
            smtp.Host = "smtp.gmail.com"

            email = New MailMessage()
            email.From = New MailAddress(txtUsername.Text)
            email.To.Add(txtTo.Text)
            email.Subject = txtSubject.Text
            email.IsBodyHtml = False
            email.Body = richTxtBody.Text
            email.Priority = MailPriority.High

            smtp.Send(email)
            MsgBox("Message Sent Successfully.", MsgBoxStyle.Information)

        Catch ex As Exception
            MsgBox(ex.Message, MsgBoxStyle.Critical)

        End Try
    End Sub
End Class

Please help me with the error... I used the port for the gmail smtp server 587 but the application gave an exception "smtp server not responding". so i googled and discovered gmail new smtp port to be 465 which i used. Now if i click the send button, the application delays for some minute and finally gives the error "the operation has timed out" ... please what is the problem with the code, i mean what am i doing wrong. or do i have to configure my gmail account to allow me use it as a gateway for smtp? .