This article explains how to add calendars in Outlook Web App, covering both the modern and classic interfaces. It includes steps for adding organizational calendars and publicly shared internet calendars, along with a note on URL formatting for Office 365 users.
How to open a Shared Mailbox to Perform Mail Merge on Outlook
This guide explains how to assign, modify, or remove delegate access in Outlook for Mac. Delegates can manage your calendar and email depending on the permissions you assign. For simple viewing access, use calendar or folder sharing instead