SMTP Problem

Imports System.Net.Mail
Public Class Form2
    Dim EmailAddress As String
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        If My.Settings.Register = False Then
            Select Case MsgBox("Before you can save changes to Launcher Maker Elite you" & vbCrLf & "must register the program." & vbCrLf & vbCrLf & "Do you want to register Launcher Maker Elite?", MsgBoxStyle.YesNo, )
                Case MsgBoxResult.Yes

                    EmailAddress = InputBox("Please enter the email address that the registration" & vbCrLf & "key will be sent to.")

                    Dim SmtpServer As New SmtpClient()

                    Dim mail As New MailMessage()

                    SmtpServer.Credentials = New System.Net.NetworkCredential("noreply.launchemrmakerelite@gmail.com", "***************")
                    SmtpServer.Host = "smtp.gmail.com"
                    SmtpServer.Port = 587
                    SmtpServer.EnableSsl = True

                    mail.From = New MailAddress("noreply.launchermakerelite@gmail.com")
                    mail.To.Add(EmailAddress)
                    mail.Subject = "Launcher Maker Elite Registration"
                    mail.Body = "This is for testing SMTP mail."

                    SmtpServer.Send(mail)

                Case (MsgBoxResult.No)

            End Select

        ElseIf My.Settings.Register = True Then

        End If
    End Sub
End Class

The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.5.1 Authentication Required.