Request to answer for Checking valid Email

string email ="^([a-zA-Z0-9_\\-\\.]+)@((\\[[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.)|(([a-zA-Z0-9\\-]+\\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\\]?)$";
           Regex r = new Regex (email);
           if (r.IsMatch(txtemailid.Text))
           {
               return true;
           }
           else
           {
               MessageBox.Show("Please Enter proper EmailId"","Employee Form", MessageBoxButtons.OK, MessageBoxIcon.Information);
               return false;

           }