using System;

​

public class Program

{

    public static void Main()

    {

        var emailaddress = "lo_@mc.com";

        Console.WriteLine($"Is {emailaddress} valid? {IsValidEmail(emailaddress).ToString()}");

    }

​

    static bool IsValidEmail(string email)

    {

        try

        {

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

            return addr.Address == email;

        }

        catch

        {

            return false;

        }

    }

}