When delegating your calendar, you can determine the level of access that the delegate has to your calendar.

You must use the Exchange admin center (EAC), to assign permissions to delegates. EAC is a web-based management console, which was introduced in Exchange Server 2013. The Exchange Management Console (EMC) or the Exchange Control Panel (ECP) can be used for older versions of Exchange Server. Using EAC, you can set the following permissions to define the activities that delegates can perform.
  • Full Access- Allows the delegate to open the delegator's account and view, add, and modify the contents of the account.
  • On behalf of- Allows the delegate to send messages on behalf of their delegator.
  • Send As- Allows the delegate to send messages as if they came directly from the mailbox. This permission is used for shared mailboxes.

You can also assign permissions for a delegate calendar by using Exchange Online and desktop Outlook applications. However, if you want to use delegate mailboxes, shared mailboxes, or shared calendars, you must configure sharing in the Exchange admin center.