Email Validation in .Net

Function for Email Validation

1. It allows max 5 dots(.) including .com and max 5 hyphen(-)
2. Only 4 Special Characters allowed are (- _ . @)
3. @ character is allowed only once and is mandatory.

private bool email()

{

      string pattern = @"^([a-zA-Z0-9])+([\w_\.\-]([a-zA-Z0-9])*[a-zA-Z0-9])*@([a-zA-Z0-9_\-\.]+)\.([a-zA-Z]{2,5}$)";

      System.Text.RegularExpressions.Match match = Regex.Match(textBox1.Text.Trim(), pattern, RegexOptions.IgnoreCase);

      if ((match.Success))

      {

            string[] words = Regex.Split(textBox1.Text.Trim(), "@");

            string word1 = words[1].ToString();

            int dotCount = word1.Count(f => f == '.');

            int hyfenCount = word1.Count(f => f == '-');

            if (!(dotCount < 6))

            {

                  MessageBox.Show("Invalid Email-id");

                  return false;

            }

            else if (!(hyfenCount < 6))

            {

                  MessageBox.Show("Invalid Email");

                  return false;

            }

            else

            {

                  MessageBox.Show("valid Email");

                  return true;

            }

      }

      else

      {

            MessageBox.Show("Invalid Email");

            return false;

      }

}