// Credentials
            var credentials = new NetworkCredential("someEmail@gmail.com", "somePassword");

            // Mail message
            var mail = new MailMessage()
            {
               From = new MailAddress("someEmail@gmail.com"),
               Subject = "Test email.",
               Body = "Test email body"
            };

            mail.To.Add(new MailAddress("someEmail@gmail.com"));

            // Smtp client
            var client = new SmtpClient()
            {
               Port = 587,
               DeliveryMethod = SmtpDeliveryMethod.Network,
               UseDefaultCredentials = false,
               Host = "smtp.gmail.com",
               EnableSsl = true,
               Credentials = credentials
            };

            // Send it...
            client.Send(mail);