use the code :
Dim s As New SmtpClient
s.Host = "smtp.gmail.com"
s.Port = 587
s.EnableSsl = True
s.Credentials = New NetworkCredential("youremail@gmail.com", "yourpassord")
Dim m As New MailMessage
m.To.Add("useremail@hotmail.com")
m.From = New MailAddress("youremail@gmail.com")
m.Subject = "subiect text"
m.Body = "email body text"
s.Send(m)
Label6.Text = "sent email"