What's wrong with this code, part 8 - Email Address Validation

It's time for another "What's wrong with this code".

Today's example is really simple, and hopefully easy.  It's a snippet of code I picked up from the net that's intended to validate an email address (useful for helping to avoid SQL injection attacks, for example).

 

    /// <summary>    /// Validate an email address provided by the caller.    ///     /// Taken from https://www.codeproject.com/aspnet/Valid_Email_Addresses.asp    /// </summary>    public static bool ValidateEmailAddress(string emailAddress)    {        string strRegex = @"^([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}" +                          @"\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\" +                           @".)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$";        System.Text.RegularExpressions.Regex re = new System.Text.RegularExpressions.Regex(strRegex);        if (re.IsMatch(emailAddress))            return (true);        else        return (false);    }

As always, my next post (Monday) will include the answers and kudos to all those who got it right (and who f