Do you see any errors in your c20.log (<Install path>/server/c2o/log/)?
Select "Use a secure SMTP connection" at the bottom of the page. I see you are using port 993 and outlook.office365.com which is accurate.
Can you test connectivity outside of Process Automation through telnet?
telnet outlook.office365.com 993
Does this work? It should return what appears to be an empty command window which is waiting for further commands, if it fails you should get an error which you can discuss with your network team.
Thank you.