stream_socket_client() working on localhost but not on aws server for "tcp://mx00.mail.com:25" to validate email

Question

We are trying to validate the email on our website and skip filling in the fake email on the quote form by the end user. we are using stream_socket_client() to check the "tcp://mx00.mail.com:25" It's working fine on our localhost Xampp Server but when we are deploying it to the live server it gets stuck and returns the timeout.

 public function check($email) { 
        $result = FALSE; 

        if (!self::validate($email)) { 
            $this->set_error("{$email} incorrect e-mail"); 
            $this->edebug($this->ErrorInfo); 
            if ($this->exceptions) { 
                throw new verifyEmailException($this->ErrorInfo); 
            } 
            return FALSE; 
        } 
        $this->error_count = 0; // Reset errors 
        $this->stream = FALSE; 

        $mxs = $this->getMXrecords(self::parse_email($email)); 
        $timeout = ceil($this->max_connection_timeout / count($mxs)); 
        foreach ($mxs as $host) { 
            /** 
             * suppress error output from stream socket client... 
             * Thanks Michael. 
             */ 
            $this->stream = @stream_socket_client("tcp://" . $host . ":" . $this->port, $errno, $errstr, $timeout); 
            if ($this->stream === FALSE) { 
                if ($errno == 0) { 
                    $this->set_error("Problem initializing the socket"); 
                    $this->edebug($this->ErrorInfo); 
                    if ($this->exceptions) { 
                        throw new verifyEmailException($this->ErrorInfo); 
                    } 
                    return FALSE; 
                } else { 
                    $this->edebug($host . ":" . $errstr); 
                } 
            } else { 
                stream_set_timeout($this->stream, $this->stream_timeout); 
                stream_set_blocking($this->stream, 1); 

                if ($this->_streamCode($this->_streamResponse()) == '220') { 
                    $this->edebug("Connection success {$host}"); 
                    break; 
                } else { 
                    fclose($this->stream); 
                    $this->stream = FALSE; 
                } 
            } 
        } 

        if ($this->stream === FALSE) { 
            $this->set_error("All connection fails"); 
            $this->edebug($this->ErrorInfo); 
            if ($this->exceptions) { 
                throw new verifyEmailException($this->ErrorInfo); 
            } 
            return FALSE; 
        } 

        $this->_streamQuery("HELO " . self::parse_email($this->from)); 
        $this->_streamResponse(); 
        $this->_streamQuery("MAIL FROM: <{$this->from}>"); 
        $this->_streamResponse(); 
        $this->_streamQuery("RCPT TO: <{$email}>"); 
        $code = $this->_streamCode($this->_streamResponse()); 
        $this->_streamResponse(); 
        $this->_streamQuery("RSET"); 
        $this->_streamResponse();
        $code2 = $this->_streamCode($this->_streamResponse()); 
        $this->_streamQuery("QUIT"); 
        fclose($this->stream); 
        
        $code = !empty($code2)?$code2:$code;
        switch ($code) { 
            case '250': 
            /** 
             * http://www.ietf.org/rfc/rfc0821.txt 
             * 250 Requested mail action okay, completed 
             * email address was accepted 
             */ 
            case '450': 
            case '451': 
            case '452': 
                /** 
                 * http://www.ietf.org/rfc/rfc0821.txt 
                 * 450 Requested action not taken: the remote mail server 
                 * does not want to accept mail from your server for 
                 * some reason (IP address, blacklisting, etc..) 
                 * Thanks Nicht Lieb. 
                 * 451 Requested action aborted: local error in processing 
                 * 452 Requested action not taken: insufficient system storage 
                 * email address was greylisted (or some temporary error occured on the MTA) 
                 * i believe that e-mail exists 
                 */ 
                return TRUE;
            case '550':
                return FALSE; 
            default : 
                return FALSE; 
        } 
    } 

For Reference: Click Here