public static string ReturnStoreResponse(string tag, string argument, string userSession, string userMailBox, bool fromUIDCommand = false)
        {
            var math = Regex.Match(argument, @"^((?:(?:(?:[1-9]+|\*):(?:[1-9]+|\*)|[1-9]+),)*(?:(?:[1-9]+|\*):(?:[1-9]+|\*)|[1-9]+)) ([^\s]+) \(([^\(\)]*)\)");

            if (!math.Success)
            {
                return(ReturnParseErrorResponse(tag, "STORE"));
            }
            string item = math.Groups[2].Value;

            if (!math.Success)
            {
                return(ReturnParseErrorResponse(tag, "FETCH"));
            }
            List <MailInfo> tempMailInfoList;
            List <MailInfo> mailInfoList = new List <MailInfo>();
            string          right        = "";
            string          left         = "";

            string[] mailIndexArr = math.Groups[1].Value.Split(',');
            foreach (string mailIndex in mailIndexArr)
            {
                if (mailIndex.Contains(':'))
                {
                    string[] temp = mailIndex.Split(':', StringSplitOptions.RemoveEmptyEntries);
                    if (temp[0] == "*")
                    {
                        if (fromUIDCommand)
                        {
                            left = "uid";
                        }
                        else
                        {
                            left = "numrow";
                        }
                    }
                    else
                    {
                        left = temp[0];
                    }
                    if (temp[1] == "*")
                    {
                        if (fromUIDCommand)
                        {
                            right = "uid";
                        }
                        else
                        {
                            right = "numrow";
                        }
                    }
                    else
                    {
                        right = temp[1];
                    }
                    if (fromUIDCommand)
                    {
                        tempMailInfoList = SqliteQuery.LoadMailInfoWithUID(userSession, userMailBox, left, right);
                    }
                    else
                    {
                        tempMailInfoList = SqliteQuery.LoadMailInfoWithIndex(userSession, userMailBox, left, right);
                    }
                }
                else
                {
                    if (fromUIDCommand)
                    {
                        tempMailInfoList = SqliteQuery.LoadMailInfoWithUID(userSession, userMailBox, mailIndex);
                    }
                    else
                    {
                        tempMailInfoList = SqliteQuery.LoadMailInfoWithIndex(userSession, userMailBox, mailIndex);
                    }
                }
                foreach (MailInfo tempMail in tempMailInfoList)
                {
                    if (!mailInfoList.Contains(tempMail))
                    {
                        mailInfoList.Add(tempMail);
                    }
                }
            }
            mailInfoList.Sort((x, y) => x.uid.CompareTo(y.uid));
            string newArgument = math.Groups[1].Value + " (FLAGS)";
            Flags  flags       = new Flags();
            int    success;

            if (math.Groups[3].Value != "")
            {
                string[] flagsArr = math.Groups[3].Value.Split(' ');
                if (!flags.BuildFlagItem(flagsArr))
                {
                    return(ReturnParseErrorResponse(tag, "STORE"));
                }
            }

            switch (item.ToLower())
            {
            case "flags":
                if (flags.seen != "1")
                {
                    flags.seen = "0";
                }
                if (flags.answered != "1")
                {
                    flags.answered = "0";
                }
                if (flags.flagged != "1")
                {
                    flags.flagged = "0";
                }
                if (flags.deleted != "1")
                {
                    flags.deleted = "0";
                }
                if (flags.draft != "1")
                {
                    flags.draft = "0";
                }
                foreach (MailInfo mailInfo in mailInfoList)
                {
                    success = SqliteQuery.UpdateFlagsWithUID(userSession, userMailBox, mailInfo.uid.ToString(), flags);
                }
                return(Response.StoreFormatReturn(tag, newArgument, userSession, userMailBox, fromUIDCommand));

            case "flags.silent":
                if (flags.seen != "1")
                {
                    flags.seen = "0";
                }
                if (flags.answered != "1")
                {
                    flags.answered = "0";
                }
                if (flags.flagged != "1")
                {
                    flags.flagged = "0";
                }
                if (flags.deleted != "1")
                {
                    flags.deleted = "0";
                }
                if (flags.draft != "1")
                {
                    flags.draft = "0";
                }
                foreach (MailInfo mailInfo in mailInfoList)
                {
                    success = SqliteQuery.UpdateFlagsWithUID(userSession, userMailBox, mailInfo.uid.ToString(), flags);
                }
                return(tag + " OK STORE completed");

            case "+flags":
                foreach (MailInfo mailInfo in mailInfoList)
                {
                    success = SqliteQuery.UpdateFlagsWithUID(userSession, userMailBox, mailInfo.uid.ToString(), flags);
                }
                return(Response.StoreFormatReturn(tag, newArgument, userSession, userMailBox, fromUIDCommand));

            case "+flags.silent":
                foreach (MailInfo mailInfo in mailInfoList)
                {
                    success = SqliteQuery.UpdateFlagsWithUID(userSession, userMailBox, mailInfo.uid.ToString(), flags);
                }
                return(tag + " OK STORE completed");

            case "-flags":
                if (flags.seen == "1")
                {
                    flags.seen = "0";
                }
                if (flags.answered == "1")
                {
                    flags.answered = "0";
                }
                if (flags.flagged == "1")
                {
                    flags.flagged = "0";
                }
                if (flags.deleted == "1")
                {
                    flags.deleted = "0";
                }
                if (flags.draft == "1")
                {
                    flags.draft = "0";
                }
                foreach (MailInfo mailInfo in mailInfoList)
                {
                    success = SqliteQuery.UpdateFlagsWithUID(userSession, userMailBox, mailInfo.uid.ToString(), flags);
                }
                return(Response.StoreFormatReturn(tag, newArgument, userSession, userMailBox, fromUIDCommand));

            case "-flags.silent":
                if (flags.seen == "1")
                {
                    flags.seen = "0";
                }
                if (flags.answered == "1")
                {
                    flags.answered = "0";
                }
                if (flags.flagged == "1")
                {
                    flags.flagged = "0";
                }
                if (flags.deleted == "1")
                {
                    flags.deleted = "0";
                }
                if (flags.draft == "1")
                {
                    flags.draft = "0";
                }
                foreach (MailInfo mailInfo in mailInfoList)
                {
                    success = SqliteQuery.UpdateFlagsWithUID(userSession, userMailBox, mailInfo.uid.ToString(), flags);
                }
                return(tag + " OK STORE completed");

            default:
                return(ReturnParseErrorResponse(tag, "STORE"));
            }
        }
        public static string ReturnAppendResponse(string tag, string argument, string userSession, AppendCall appendCall)
        {
            //var maths = Regex.Match(argument, "");
            var math = Regex.Match(argument, "^(?:((?:\"[\\w\\s]+\"|\\w+) \\((?:\\\\\\w+)*\\) \"[^\"]*\" \\{\\d*\\})|((?:\"[\\w\\s]+\"|\\w+) \\((?:\\\\\\w+)*\\) \\{\\d*\\})|((?:\"[\\w\\s]+\"|\\w+) \\{\\d*\\}))");

            if (!math.Success)
            {
                return(Response.ReturnParseErrorResponse(tag, "APPEND"));
            }
            MailInfo      mailAppend = new MailInfo();
            Flags         flags      = new Flags();
            string        mailBoxName;
            List <string> strFlag     = new List <string>();
            DateTime      Date        = DateTime.Now;
            int           messageSize = 0;

            if (math.Groups[3].Success)
            {
                math        = Regex.Match(math.Groups[3].Value, "(?:(\"[\\w\\s]+\"|\\w+) \\{(\\d*)\\})");
                mailBoxName = math.Groups[1].Value.Replace("\"", "");
                if (math.Groups[2].Value != "" && !Int32.TryParse(math.Groups[3].Value, out messageSize))
                {
                    return(Response.ReturnParseErrorResponse(tag, "APPEND"));
                }
            }
            else
            {
                if (math.Groups[2].Success)
                {
                    math        = Regex.Match(math.Groups[2].Value, "(?:(\"[\\w\\s]+\"|\\w+) \\(((?:\\\\\\w+)*)\\) \\{(\\d*)\\})");
                    mailBoxName = math.Groups[1].Value.Replace("\"", "");
                    if (math.Groups[2].Value != "")
                    {
                        strFlag = math.Groups[2].Value.Split(' ').ToList();
                    }
                    if (math.Groups[3].Value != "" && !Int32.TryParse(math.Groups[3].Value, out messageSize))
                    {
                        return(Response.ReturnParseErrorResponse(tag, "APPEND"));
                    }
                }
                else
                {
                    math        = Regex.Match(math.Groups[1].Value, "(?:(\"[\\w\\s]+\"|\\w+) \\(((?:\\\\\\w+)*)\\) \"([^\"]*)\" \\{(\\d*)\\})");
                    mailBoxName = math.Groups[1].Value.Replace("\"", "");
                    if (math.Groups[2].Value != "")
                    {
                        strFlag = math.Groups[2].Value.Split(' ').ToList();
                    }
                    if (math.Groups[3].Value != "")
                    {
                        try
                        {
                            Date = Convert.ToDateTime(math.Groups[3].Value);
                        }
                        catch
                        {
                            return(Response.ReturnParseErrorResponse(tag, "APPEND"));
                        }
                    }
                    if (math.Groups[4].Value != "" && !Int32.TryParse(math.Groups[4].Value, out messageSize))
                    {
                        return(Response.ReturnParseErrorResponse(tag, "APPEND"));
                    }
                }
            }
            List <MailBoxInfo> mailBoxInfoList = SqliteQuery.LoadMailBoxInfo(userSession, mailBoxName);

            if (mailBoxInfoList.Count == 0)
            {
                return(tag + " NO Mailbox does not exist");
            }
            if (!flags.BuildFlagItem(strFlag.ToArray()))
            {
                return(Response.ReturnParseErrorResponse(tag, "APPEND"));
            }
            mailAppend.user        = userSession;
            mailAppend.mailboxname = mailBoxName;
            mailAppend.uid         = mailBoxInfoList[0].uidnext;
            mailAppend.recent      = 1;
            mailAppend.seen        = (flags.seen == "1" ? 1 : 0);
            mailAppend.answered    = (flags.answered == "1" ? 1 : 0);
            mailAppend.deleted     = (flags.deleted == "1" ? 1 : 0);
            mailAppend.draft       = (flags.draft == "1" ? 1 : 0);
            mailAppend.flagged     = (flags.flagged == "1" ? 1 : 0);
            mailAppend.intertime   = ((DateTimeOffset)Date).ToUnixTimeSeconds();
            appendCall.isCall      = true;
            appendCall.mailInfo    = mailAppend;
            appendCall.size        = messageSize;
            appendCall.tag         = tag;
            return("+ Ready for append literal");
        }