Mac Mail app: "cannot connect to account "Hotmail" and Hotmail is Offline

Mac version: 10.13.6

Mac Mail app: "cannot connect to account "Hotmail" - enter password: my correct Hotmail/Microsoft password fails to verify. Connection Doctor says Hotmail is "offline". Methods to bring it back online don't work. Apple internet advice: contact your email provider (Microsoft) to verity your account details and setup. So far all I can get in contact with Microsoft other than the "Virtual Assistant" who is useless.

Any help would be very much appreciated.