Good news - I HAVE RESOLVED the issue
Turns out my employer created their own site certificate and Outlook didn't like that. Once I manually added the certificate to my computer Outlook works!!
Best part I don't need a VPN either.
I don't believe the certificate issue was the original problem as I didn't see it before we moved to the new email server and my cell phone didn't let me connect using Outlook on the new server either.
Thanks again to ALL who have helped.
This is truly a very supportive community.