using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("All these must evaluata to valid = true");

        Console.WriteLine(IsValidEmail("simple@example.com"));

Console.WriteLine(IsValidEmail("very.common@example.com"));

Console.WriteLine(IsValidEmail("disposable.style.email.with+symbol@example.com"));

Console.WriteLine(IsValidEmail("other.email-with-hyphen@example.com"));

Console.WriteLine(IsValidEmail("fully-qualified-domain@example.com"));

Console.WriteLine(IsValidEmail("user.name+tag+sorting@example.com"));  //(may go to user.name@example.com inbox depending on mail server)

Console.WriteLine(IsValidEmail("x@example.com"));// (one-letter local-part)

Console.WriteLine(IsValidEmail("example-indeed@strange-example.com"));//

Console.WriteLine(IsValidEmail("admin@mailserver1"));// (local domain name with no TLD, although ICANN highly discourages dotless email addresses)

Console.WriteLine(IsValidEmail("example@s.example"));// (see the List of Internet top-level domains)

Console.WriteLine(IsValidEmail("\" \"@example.org"));// (space between the quotes)

Console.WriteLine(IsValidEmail("\"john..doe\"@example.org"));// (quoted double dot)

Console.WriteLine(IsValidEmail("mailhost!username@example.org"));// (bangified host route used for uucp mailers)

Console.WriteLine(IsValidEmail("user%example.com@example.org"));// (% escaped mail route to user@example.com via example.org)

​

Console.WriteLine("All these must evaluata to valid = false");

Console.WriteLine(IsValidEmail("Abc.example.com"));  // (no @ character)

Console.WriteLine(IsValidEmail("A@b@c@example.com"));  // (only one @ is allowed outside quotation marks)

Console.WriteLine(IsValidEmail(@"a""b(c)d,e:f;g<h>i[j\k]l@example.com"));  // (none of the special characters in this local-part are allowed outside quotation marks)

Console.WriteLine(IsValidEmail("just\"not\"right@example.com"));  // (quoted strings must be dot separated or the only element making up the local-part)

Console.WriteLine(IsValidEmail(@"this is""not\allowed@example.com"));  // (spaces, quotes, and backslashes may only exist when within quoted strings and preceded by a backslash)

Console.WriteLine(IsValidEmail(@"this\ still\""not\\allowed@example.com"));  // (even if escaped (preceded by a backslash), spaces, quotes, and backslashes must still be contained by quotes)

Console.WriteLine(IsValidEmail("1234567890123456789012345678901234567890123456789012345678901234+x@example.com"));  // (local part is longer than 64 characters)"));

    }

    static bool IsValidEmail(string email)

{

    try {

        var addr = new System.Net.Mail.MailAddress(email);

        return addr.Address == email;

    }

    catch {

        return false;

    }

}

}