Outlook.com Mail, Calendar, Contacts on Mac
These are easy steps to add Outlook.com Account to your Mac.
1, System preferences -> Internet Accounts -> Add -> Exchange
2, Write your Email and Password (If you use Two Factor Authentication, generate password with: https://account.live.com/proofs/AppPassword?mkt=en-us)
3, Then it asks Internal Server and External Server so those are both outlook.office365.com