Iphone can't synchronize with exchange server 2003

One of my coworkers in the IT department renewed the certificate on the exchange server 2003. After renew, all iphones in the company can't retrieve their emails.

I used the test tool: https://www.testexchangeconnectivity.com/#&&v5i2iAnCJChhVE6++cacUpPTGrs5QPa+X0lS0igiutd8hfjFgzVDW6gQkz4iH8UhMNDxtD1X8K0srNbEhGksHzsAF8D9MV7nVZV6yZr7qXqhLo1ahzMd3POcVezdXMdm3r2qmHe4cTMNXE7YRJ1PqrcFSbmthIXRNJe1ZYu0Zh50lKtrqiZ45MJT6Q1BwnWquNo6zQ==

and the result shows:
"Testing the SSL certificate to make sure it's valid.
       The SSL certificate failed one or more certificate validation checks."

I attached the print screen for this error. Also, i did a port test on http://www.yougetsignal.com/tools/open-ports/, the result says the port "Port 443 is closed on XXX.XX.242.131."

this is the report from the testexchangeconnectivity.com. I checked another article on EE, it's this one: https://www.experts-exchange.com/Software/Server_Software/Email_Servers/Exchange/A_1798-Exchange-2003-Activesync-Connection-Problems-FAQ.html.


Dear experts here, could you please help me with this. I know it's new year eve and most of you maybe stay at home enjoying time with your families. But I really don't want to my coworkers isolated with company email.

thank you.