Hi everyone,
This might end up being a dumb question, but I’m going cross-eyed trying to figure this out.
I’m setting up a fresh Exchange server, I requested a certificate for the following addresses:
autodiscover.mydomain.ca and mail.mydomain.ca
The request came through fine and I was issued a certificate that will expire in 89 days, but if I run the test I get that it failed due to: The website root path for mail.mydomain.ca could not be determined. Request cannot continue.
What could I have set up incorrectly? Or have going on?
No such thing as a dumb question 
if you’re on the latest version of the app this shouldn’t be a problem but there may well be something that needs fixed.
If you’re getting your certificate OK then it’s nothing to really worry about - we actually only use the filesystem website root path as a fallback if the built-in http validation service can’t run, so in most cases it doesn’t get involved in actual certificate requests but we check it during Test anyway.
What is your Site Root Directory set to under Authorization > http? It should be blank for auto (which we read from IIS) otherwise that’s the path the app will try to write http challenge response files (it creates the files as /.well-known/acme-challenge/<filename>).