Outlook on Exchange Server will not connect to Zoho CRM

Outlook on Exchange Server will not connect to Zoho CRM

We have tried every configuration we can think of. My IT person is at her wits end. All of our devices, iphones, laptops, etc., connect with no problem to outlook, but we can get nowhere with Zoho CRM. If I can get some help it would be a blessing. I am weeks behind on implementation and I need to get going. I will put my IT person, Lisa on this question to help craft a solution. Thank you so much from desperate. (John)