Add delegate for your Calendar, Mail, Contacts

General Info

Allow someone else to manage your mail and calendar (microsoft.com)

Delegate Methods (Depending on your Outlook Platform):

How to add in New Outlook 

How to add in Classic Outlook (This is the Recommended way to get access to all delegate settings, but you'll need to be on Windows.)

How to add in Outlook on the Web

How to add in Outlook on macOS