1. Open Apple Calendar.
2. On the top menu bar, Navigate to Calendar > Preferences and then select Accounts.
3. On the left-hand side, select Exchange, and then click the Delegation tab.
4. This is the delegation panel that allows you, if you have the right permissions, to add team and colleague calendars. To add a new calendar, click on the plus icon. 
   • If you are not able to add a team calendar, contact ITHelp@isoc.org.
   • If you are not able to add a colleague's calendar, contact them directly.
     • If you would like to give a colleague access to your calendar, refer to the article here.
5. Start by typing the first few letters of the account and select the account name from the drop-down list. Once selected, the columns 'Calendars' and 'Tasks' will indicate what permissions you have for the selected Users. Click on the box next to the username to show display the calendar. You have now added the shared calendar to Apple Mail.
6. When you go back to your Calendar, On the left menu, you will see a new section called 'Delegates' with the name of the user followed by the calendars shared with you. 

Note: It will take some time for the user's calendar to load onto yours, so do not be alarmed if you do not see the events right away.