Our domain, say X.Y, is having issues opening webmail.X.Y on some browsers. We have a DNS record pointing to the Office 365 outlook web app URL.
Are you able to check into this to see what the solution might be? It seems like Google Chrome and Safari it works fine, but Firefox and Brave show the error below. This has happened on several different devices, internet connections and days.
This site can’t provide a secure connection
An SSL error has occurred and a secure connection to the server cannot be made.