Office 365, Email, Exchange, Delegates
How do I give someone the ability to send messages for me or manage my calendar with Exchange and Outlook?
Similar to having an assistant that helps you manage your incoming paper mail, another person, known as a delegate, can receive and respond to email messages and meeting requests and responses on your behalf. You can also grant the delegate additional permissions to read, create, or change items in your Microsoft Exchange Server mailbox.
How to add and manage delegates:
Windows: See Microsoft's page.
Mac: See Microsoft's page.
Note: If you are using Outlook on the web, assigning delegate permissions is not a feature since you can't open shared calendars as you can in Outlook desktop.
Using your deletegate permissions:
For instructions on how to manage someone else's email and calendar, see here.