SMTP::sendCommand( string $command, string $commandstring, int|array $expect ): bool

1084    protected function sendCommand($command, $commandstring, $expect)1085    {1086        if (!$this->connected()) {1087            $this->setError("Called $command without being connected");1088 1089            return false;1090        }1091        //Reject line breaks in all commands1092        if ((strpos($commandstring, "\n") !== false) || (strpos($commandstring, "\r") !== false)) {1093            $this->setError("Command '$command' contained line breaks");1094 1095            return false;1096        }1097        $this->client_send($commandstring . static::LE, $command);1098 1099        $this->last_reply = $this->get_lines();1100        //Fetch SMTP code and possible error code explanation1101        $matches = [];1102        if (preg_match('/^([\d]{3})[ -](?:([\d]\\.[\d]\\.[\d]{1,2}) )?/', $this->last_reply, $matches)) {1103            $code = (int) $matches[1];1104            $code_ex = (count($matches) > 2 ? $matches[2] : null);1105            //Cut off error code from each response line1106            $detail = preg_replace(1107                "/{$code}[ -]" .1108                ($code_ex ? str_replace('.', '\\.', $code_ex) . ' ' : '') . '/m',1109                '',1110                $this->last_reply1111            );1112        } else {1113            //Fall back to simple parsing if regex fails1114            $code = (int) substr($this->last_reply, 0, 3);1115            $code_ex = null;1116            $detail = substr($this->last_reply, 4);1117        }1118 1119        $this->edebug('SERVER -> CLIENT: ' . $this->last_reply, self::DEBUG_SERVER);1120 1121        if (!in_array($code, (array) $expect, true)) {1122            $this->setError(1123                "$command command failed",1124                $detail,1125                $code,1126                $code_ex1127            );1128            $this->edebug(1129                'SMTP ERROR: ' . $this->error['error'] . ': ' . $this->last_reply,1130                self::DEBUG_CLIENT1131            );1132 1133            return false;1134        }1135 1136        //Don't clear the error store when using keepalive1137        if ($command !== 'RSET') {1138            $this->setError('');1139        }1140 1141        return true;1142    }