using System.Text.RegularExpressions;
public static void Main()
Console.WriteLine(IsValidEmail("-}$!~{ac=co^'un*&t-i+ng~!^$%a@grissellsworth.com")+"");
Console.WriteLine(IsValidEmail("roshan+maharjan{roshan}{maharjan}@gr--is-se_lls.wo-rth.mobile")+"");
Console.WriteLine(IsValidEmail("!accounting@worth.com")+"");
Console.WriteLine(IsValidEmail("\"roshan.maharjan\"@gmail.com")+"");
Console.WriteLine(IsValidEmail("accounting@localserver")+"");
Console.WriteLine(IsValidEmail("\"roshan@nyc\"_ny@gmail.com")+"");
public static bool IsValidEmail(string a_email)
string v_pattern = "^([-a-zA-Z0-9~!$%^&*_=+}{\\'?]+(\\.[-a-zA-Z0-9~!$%^&*_=+}{\\'?]+)*@([0-9a-zA-Z][-\\w]*[0-9a-zA-Z]\\.)+[a-zA-Z]{2,9})$";
if (Regex.IsMatch(a_email, v_pattern))