KB ID 0001652
While trying to connect Outlook (2016) to an Office 365 email account;
We can’t connect you
It looks like we can’t connect you to one of our services the moment. Please try again later, or contact your helpdesk if the issue persists.
This was happening because my ADFS server was using a ‘self-signed’ certificate (i.e. not a purchased one). This should NEVER be done in a production environment, but this is my test network, (so I refuse to spend money on certificates for testing etc!)
I cured the problem by simply importing/trusting the CA Certificate from my internal Certificate Services CA server, (that issued the ADFS servers certificate).
If you see this on a production server, with a publicly signed certificate, check that the ‘problem’ client does not need a Windows Update, to update its trusted CA Certificates, or that your certificate simply hasn’t expired, and you ‘forgot’ to renew it. If so;
ADFS: Changing the Certificate
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