BusyCal on the mac allows you to add Microsoft Teams meetings to all your Office 365 events, which requires connecting to Microsoft's Graph interface. The new Office 365 connection type recently added in v2024.2.1 also requires access to Microsoft Graph. Your O365 account admin most likely will need to give BusyCal permissions to connect to your account, which has been explained below.

Office 365 accounts syncing via Exchange Web Services (EWS) do not support Microsoft Bookings. We have prepared a new account type (currently in beta) that uses the new Microsoft Graph API and will support Bookings.

Invitations in iCloud, Google Calendar, Exchange, and Outlook are primarily managed at the account level. When someone sends an invite, it can be delivered in two main ways: as a direct update to your calendar account (common for users on the same service such as Google Calendar or using CalDAV-compatible platforms) or as an email with an `.ics` attachment. The `.ics` file contains all the event details, such as the title, time, location, and participants, allowing recipients to accept or decline the invitation and add it to their calendar.