private void BtnSend_Click(object sender, EventArgs e)
    {

        // some other code here
        SendEmail("tosomeone@gmail.com", "Subject", "Body");
    }
    public async Task SendEmail(string toEmailAddress, string emailSubject, string emailMessage)
    {
        SmtpClient client = new SmtpClient("smtp.gmail.com", 587);
        MailMessage message = new MailMessage();
        message.From = new MailAddress("fromme@gmail.com");
        message.To.Add(toEmailAddress);
        message.Subject = emailSubject;
        message.Body = emailMessage;
        client.UseDefaultCredentials = false;
        client.EnableSsl = true;
        client.Credentials = new System.Net.NetworkCredential("fromme@gmail.com", "somepassword");

        try
        {
            client.Send(message);
        }
        catch (Exception e)
        {
            Toast.MakeText(this, "failure ", ToastLength.Long).Show();
        }