For some reason outlook clients configured for rpc/http are getting prompted for their password. What am I missing?
The RPC/HTTP test failed.
Attempting to resolve the host name mail.schulershook.com in DNS.
The host name resolved successfully.
Testing TCP port 443 on host mail.schulershook.com to ensure it's listening and open.
The port was opened successfully.
Testing the SSL certificate to make sure it's valid.
The certificate passed all validation requirements.
Checking the IIS configuration for client certificate authentication.
Client certificate authentication wasn't detected.
Testing HTTP Authentication Methods for URL https://mail.schulershook.com/rpc/rpcproxy.dll
The HTTP authentication methods are correct.
Testing SSL mutual authentication with the RPC proxy server.
Mutual authentication was verified successfully.
Attempting to ping RPC proxy mail.schulershook.com.
RPC Proxy can't be pinged.
An HTTP 401 Unauthorized response was received from the remote Unknown server. This is usually the result of an incorrect username or password. If you are attempting to log onto an Office 365 service, ensure you are using your full User Principal Name (UPN).