/// <summary>
        /// Parses header field from the specified value.
        /// </summary>
        /// <param name="value">Header field value. Header field name must be included. For example: 'Sender: [email protected]'.</param>
        /// <returns>Returns parsed header field.</returns>
        /// <exception cref="ArgumentNullException">Is raised when <b>value</b> is null reference.</exception>
        /// <exception cref="ParseException">Is raised when header field parsing errors.</exception>
        public static Mail_h_Received Parse(string value)
        {
            if (value == null)
            {
                throw new ArgumentNullException("value");
            }

            string[] name_value = value.Split(new char[] { ':' }, 2);
            if (name_value.Length != 2)
            {
                throw new ParseException("Invalid header field value '" + value + "'.");
            }

            Mail_h_Received retVal = new Mail_h_Received("a", "b", DateTime.MinValue);

            MIME_Reader r = new MIME_Reader(name_value[1]);

            while (true)
            {
                string word = r.Word();
                // We processed all data.
                if (word == null && r.Available == 0)
                {
                    break;
                }
                // We have comment, just eat it.
                else if (r.StartsWith("("))
                {
                    r.ReadParenthesized();
                }
                // We have date-time or unknown-data.
                else if (r.StartsWith(";"))
                {
                    // Eat ';'
                    r.Char(false);

                    try{
                        retVal.m_Time = MIME_Utils.ParseRfc2822DateTime(r.QuotedReadToDelimiter(new char[] { ';' }));
                    }
                    catch {
                        // We hane some unknown data, skip it.
                    }
                }
                else
                {
                    // We have some unexpected char like: .,= ... . Just eat it.
                    if (word == null)
                    {
                        r.Char(true);
                        continue;
                    }

                    word = word.ToUpperInvariant();

                    if (word == "FROM")
                    {
                        retVal.m_From = r.DotAtom();

                        r.ToFirstChar();
                        if (r.StartsWith("("))
                        {
                            string[] parts = r.ReadParenthesized().Split(' ');
                            if (parts.Length == 1)
                            {
                                if (Net_Utils.IsIPAddress(parts[0]))
                                {
                                    retVal.m_pFrom_TcpInfo = new Mail_t_TcpInfo(IPAddress.Parse(parts[0]), null);
                                }
                            }
                            else if (parts.Length == 2)
                            {
                                if (Net_Utils.IsIPAddress(parts[1]))
                                {
                                    retVal.m_pFrom_TcpInfo = new Mail_t_TcpInfo(IPAddress.Parse(parts[1]), parts[0]);
                                }
                            }
                        }
                    }
                    else if (word == "BY")
                    {
                        retVal.m_By = r.DotAtom();

                        r.ToFirstChar();
                        if (r.StartsWith("("))
                        {
                            string[] parts = r.ReadParenthesized().Split(' ');
                            if (parts.Length == 1)
                            {
                                if (Net_Utils.IsIPAddress(parts[0]))
                                {
                                    retVal.m_pBy_TcpInfo = new Mail_t_TcpInfo(IPAddress.Parse(parts[0]), null);
                                }
                            }
                            else if (parts.Length == 2)
                            {
                                if (Net_Utils.IsIPAddress(parts[1]))
                                {
                                    retVal.m_pBy_TcpInfo = new Mail_t_TcpInfo(IPAddress.Parse(parts[1]), parts[0]);
                                }
                            }
                        }
                    }
                    else if (word == "VIA")
                    {
                        retVal.m_Via = r.Word();
                    }
                    else if (word == "WITH")
                    {
                        retVal.m_With = r.Word();
                    }
                    else if (word == "ID")
                    {
                        // msg-id = [CFWS] "<" id-left "@" id-right ">" [CFWS]

                        if (r.StartsWith("<"))
                        {
                            retVal.m_ID = r.ReadParenthesized();
                        }
                        else
                        {
                            retVal.m_ID = r.Atom();
                        }
                    }
                    else if (word == "FOR")
                    {
                        r.ToFirstChar();

                        // path / angle-address
                        if (r.StartsWith("<"))
                        {
                            retVal.m_For = r.ReadParenthesized();
                        }
                        else
                        {
                            string mailbox = Mail_Utils.SMTP_Mailbox(r);
                            if (mailbox == null)
                            {
                                throw new ParseException("Invalid Received: For parameter value '" + r.ToEnd() + "'.");
                            }
                            retVal.m_For = mailbox;
                        }
                    }
                    // Unknown, just eat value.
                    else
                    {
                        r.Word();
                    }
                }
            }

            retVal.m_ParseValue = value;

            return(retVal);
        }
        /// <summary>
        /// Parses header field from the specified value.
        /// </summary>
        /// <param name="value">Header field value. Header field name must be included. For example: 'Sender: [email protected]'.</param>
        /// <returns>Returns parsed header field.</returns>
        /// <exception cref="ArgumentNullException">Is raised when <b>value</b> is null reference.</exception>
        /// <exception cref="ParseException">Is raised when header field parsing errors.</exception>
        public static Mail_h_Received Parse(string value)
        {
            if(value == null){
                throw new ArgumentNullException("value");
            }

            string[] name_value = value.Split(new char[]{':'},2);
            if(name_value.Length != 2){
                throw new ParseException("Invalid header field value '" + value + "'.");
            }

            Mail_h_Received retVal = new Mail_h_Received("a","b",DateTime.MinValue);

            MIME_Reader r = new MIME_Reader(name_value[1]);

            while(true){
                string word = r.Word();
                // We processed all data.
                if(word == null && r.Available == 0){
                    break;
                }
                // We have comment, just eat it.
                else if(r.StartsWith("(")){
                    r.ReadParenthesized();
                }
                // We have date-time.
                else if(r.StartsWith(";")){
                    // Eat ';'
                    r.Char(false);

                    retVal.m_Time = MIME_Utils.ParseRfc2822DateTime(r.ToEnd());
                }
                else{
                    // We have some unexpected char like: .,= ... . Just eat it.
                    if(word == null){
                        r.Char(true);
                        continue;
                    }

                    word = word.ToUpperInvariant();

                    if(word == "FROM"){
                        retVal.m_From = r.DotAtom();

                        r.ToFirstChar();
                        if(r.StartsWith("(")){
                            string[] parts = r.ReadParenthesized().Split(' ');
                            if(parts.Length == 1){
                                if(Net_Utils.IsIPAddress(parts[0])){
                                    retVal.m_pFrom_TcpInfo = new Mail_t_TcpInfo(IPAddress.Parse(parts[0]),null);
                                }
                            }
                            else if(parts.Length == 2){
                                if(Net_Utils.IsIPAddress(parts[1])){
                                    retVal.m_pFrom_TcpInfo = new Mail_t_TcpInfo(IPAddress.Parse(parts[1]),parts[0]);
                                }
                            }
                        }
                    }
                    else if(word == "BY"){
                        retVal.m_By = r.DotAtom();

                        r.ToFirstChar();
                        if(r.StartsWith("(")){
                            string[] parts = r.ReadParenthesized().Split(' ');
                            if(parts.Length == 1){
                                if(Net_Utils.IsIPAddress(parts[0])){
                                    retVal.m_pBy_TcpInfo = new Mail_t_TcpInfo(IPAddress.Parse(parts[0]),null);
                                }
                            }
                            else if(parts.Length == 2){
                                if(Net_Utils.IsIPAddress(parts[1])){
                                    retVal.m_pBy_TcpInfo = new Mail_t_TcpInfo(IPAddress.Parse(parts[1]),parts[0]);
                                }
                            }
                        }
                    }
                    else if(word == "VIA"){
                        retVal.m_Via = r.Word();
                    }
                    else if(word == "WITH"){
                        retVal.m_With = r.Word();
                    }
                    else if(word == "ID"){
                        // msg-id = [CFWS] "<" id-left "@" id-right ">" [CFWS]

                        if(r.StartsWith("<")){
                            retVal.m_ID = r.ReadParenthesized();
                        }
                        else{
                            retVal.m_ID = r.Atom();
                        }
                    }
                    else if(word == "FOR"){
                        r.ToFirstChar();

                        // path / angle-address
                        if(r.StartsWith("<")){
                            retVal.m_For = r.ReadParenthesized();
                        }
                        else{
                            string mailbox = Mail_Utils.SMTP_Mailbox(r);
                            if(mailbox == null){
                                throw new ParseException("Invalid Received: For parameter value '" + r.ToEnd() + "'.");
                            }
                            retVal.m_For = mailbox;
                        }
                    }
                    // Unknown, just eat value.
                    else{
                         r.Word();
                    }
                }
            }

            retVal.m_ParseValue = value;

            return retVal;
        }