To add your Office 365 email account to Outlook on Windows, follow these steps.
From the File menu in Outlook, select “Add Account”.
Enter in your account details, then click “Next”
Outlook will try to automatically configure your account. It may prompt you again for credentials.
If the account configuration was successful, you will be presented with a screen like this. Click “Finish”.
You may be prompted to restart Outlook.
After re-opening Outlook, your new account will appear at the bottom of the account/folder list. To make it easy to find new emails, add your Inbox to the Favourites.
Click and drag the Inbox folder all the way up the top to your Favourites section.