检正email的格式

下面是email正则表达式：
Ex：
string pattern = @"^[a-z][a-z|0-9|]*([_][a-z|0-9]+)*([.][a-z|0-9]+([_][a-z|0-9]+)*)?
                        @[a-z][a-z|0-9|]*\.([a-z][a-z|0-9]*(\.[a-z][a-z|0-9]*)?)$";   
   
System.Text.RegularExpressions.Match match = Regex.Match(txtEmailChecking.Text.Trim(),
                                                                                                pattern,RegexOptions.IgnoreCase);
   if(match.Success)
    MessageBox.Show("Success","Checking");
   else
    MessageBox.Show("Fail","Checking");