MS Exchange Team released a new set of tools for the EXRCA (Microsoft Remote Connectivity Analyzer). Check the original post from the team:
We’re happy to announce that we’ve added some tests to Microsoft Remote Connectivity Analyzer (RCA), to help you test your mail flow configuration. These tests are intended for customers who use the Exchange Online Protection service to perform spam and malware filtering before sending email messages to your email servers. You can run these tests when setting up the service, or whenever you want to verify that your mail flow is set up correctly.