SMTP::data( string $msg_data ): bool

736    public function data($msg_data)737    {738        //This will use the standard timelimit739        if (!$this->sendCommand('DATA', 'DATA', 354)) {740            return false;741        }742 743        /* The server is ready to accept data!744         * According to rfc821 we should not send more than 1000 characters on a single line (including the LE)745         * so we will break the data up into lines by \r and/or \n then if needed we will break each of those into746         * smaller lines to fit within the limit.747         * We will also look for lines that start with a '.' and prepend an additional '.'.748         * NOTE: this does not count towards line-length limit.749         */750 751        //Normalize line breaks before exploding752        $lines = explode("\n", str_replace(["\r\n", "\r"], "\n", $msg_data));753 754        /* To distinguish between a complete RFC822 message and a plain message body, we check if the first field755         * of the first line (':' separated) does not contain a space then it _should_ be a header, and we will756         * process all lines before a blank line as headers.757         */758 759        $field = substr($lines[0], 0, strpos($lines[0], ':'));760        $in_headers = false;761        if (!empty($field) && strpos($field, ' ') === false) {762            $in_headers = true;763        }764 765        foreach ($lines as $line) {766            $lines_out = [];767            if ($in_headers && $line === '') {768                $in_headers = false;769            }770            //Break this line up into several smaller lines if it's too long771            //Micro-optimisation: isset($str[$len]) is faster than (strlen($str) > $len),772            while (isset($line[self::MAX_LINE_LENGTH])) {773                //Working backwards, try to find a space within the last MAX_LINE_LENGTH chars of the line to break on774                //so as to avoid breaking in the middle of a word775                $pos = strrpos(substr($line, 0, self::MAX_LINE_LENGTH), ' ');776                //Deliberately matches both false and 0777                if (!$pos) {778                    //No nice break found, add a hard break779                    $pos = self::MAX_LINE_LENGTH - 1;780                    $lines_out[] = substr($line, 0, $pos);781                    $line = substr($line, $pos);782                } else {783                    //Break at the found point784                    $lines_out[] = substr($line, 0, $pos);785                    //Move along by the amount we dealt with786                    $line = substr($line, $pos + 1);787                }788                //If processing headers add a LWSP-char to the front of new line RFC822 section 3.1.1789                if ($in_headers) {790                    $line = "\t" . $line;791                }792            }793            $lines_out[] = $line;794 795            //Send the lines to the server796            foreach ($lines_out as $line_out) {797                //Dot-stuffing as per RFC5321 section 4.5.2798                //https://www.rfc-editor.org/rfc/rfc5321#section-4.5.2799                if (!empty($line_out) && $line_out[0] === '.') {800                    $line_out = '.' . $line_out;801                }802                $this->client_send($line_out . static::LE, 'DATA');803            }804        }805 806        //Message data has been sent, complete the command807        //Increase timelimit for end of DATA command808        $savetimelimit = $this->Timelimit;809        $this->Timelimit *= 2;810        $result = $this->sendCommand('DATA END', '.', 250);811        $this->recordLastTransactionID();812        //Restore timelimit813        $this->Timelimit = $savetimelimit;814 815        return $result;