My own Mailinator in 5 minutes

using System;
using System.Collections.Generic;
using System.Text;

namespace LumiSoft.Net.DNS
{
    /// <summary>
    /// This class holds DNS server responce code. Defined in RFC 1035.
    /// </summary>
    public enum DNS_RCode
    {
        /// <summary>
		/// No error condition.
		/// </summary>
		NO_ERROR = 0, 

		/// <summary>
		/// Format error - The name server was unable to interpret the query.
		/// </summary>
		FORMAT_ERRROR = 1, 

		/// <summary>
		/// Server failure - The name server was unable to process this query due to a problem with the name server.
		/// </summary>
		SERVER_FAILURE = 2, 

		/// <summary>
		/// Name Error - Meaningful only for responses from an authoritative name server, this code signifies that the
		/// domain name referenced in the query does not exist.
		/// </summary>
		NAME_ERROR = 3, 

		/// <summary>
		/// Not Implemented - The name server does not support the requested kind of query.
		/// </summary>
		NOT_IMPLEMENTED = 4,  

		/// <summary>
		/// Refused - The name server refuses to perform the specified operation for policy reasons.
		/// </summary>
		REFUSED  = 5, 
    }
}