Getting 500 from EWS API

I am trying to connect to exchange web server APIs from java. I want to configure the mail flow rules. This is the code I am using -

exchangeService = new ExchangeService(ExchangeVersion.Exchange2010_SP2);
exchangeService.setUrl(new URI("https://outlook.office365.com/EWS/exchange.asmx"));
ExchangeCredentials credentials = new TokenCredentials(accessToken);
this.exchangeService.setCredentials(credentials);
exchangeService.getInboxRules();

The account I'm trying to connect to is a trial account with a domain like - `