Email Mask for c# masktextbox

private void BtnSave_Click(object sender, EventArgs e)
{
    Regex reg = new Regex(@"^([\w\.\-]+)@([\w\-]+)((\.(\w){2,3})+)$");
    if (!reg.IsMatch(textBox1.Text))
    {
        errorProvider1.SetError(textBox1, "Email not valid");
    }

    else
    {
        errorProvider1.Dispose();
    }
}