Email Validation in asp.net

Basically we can do different type validation in asp.net which are client side and server side email validation.The client side validation has done using jquery,javascript and asp.net validation controls.Right now i will show how to perform the server side validation using regex patterns. Pattern for email:

public const string EmailPattern =
            @"^(([\w-]+\.)+[\w-]+|([a-zA-Z]{1}|[\w-]{2,}))@"
     + @"((([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\.([0-1]?
    [0-9]{1,2}|25[0-5]|2[0-4][0-9])\."
     + @"([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\.([0-1]?
    [0-9]{1,2}|25[0-5]|2[0-4][0-9])){1}|"
     + @"([a-zA-Z]+[\w-]+\.)+[a-zA-Z]{2,4})$";

note 1:Parameter-string that contains an E-Mail address.
note 2:True, when Parameter-string is not null and 
note 3: contains a valid E-Mail address;
note 4:otherwise false.

public static bool IsEmail(string email)
{
if (email != null) return Regex.IsMatch(email, MatchEmailPattern);
else return false;
}

The below function will call the valid email function which is "IsEmail", when we submit the email text box data

if (!IsEmail(email.Text))
{
strError += "Please enter a valid email address";
isValid = false;
}