# Booking Microsoft resource calendars with Free/Busy

When creating an event with a Calendar in Free/Busy access mode, Cronofy doesn't directly put the event into the calendar, but instead invites the calendar to an event via email.

In this scenario, Cronofy acts as the calendar provider and handles sending the event invitations and updates via email, with the ICS file attached.

You can set up your resource calendar to accept Cronofy events automatically, removing the need for an admin to go in and manually approve a booking.

### Configuring the resource to auto-accept invites
For these emailed invites to be accepted automatically, the calendar admin needs
to configure the resource mailbox. By default a Microsoft resource will **not**
accept invites from senders outside its own tenant, so Cronofy's invites will be
ignored without this step.

This is done with the
[`Set-CalendarProcessing`](https://learn.microsoft.com/en-us/powershell/module/exchangepowershell/set-calendarprocessing?view=exchange-ps)
cmdlet in PowerShell:

```powershell
Connect-ExchangeOnline

Set-CalendarProcessing -Identity "room@yourdomain.com" `
  -AutomateProcessing AutoAccept `
  -AllowConflicts $false `
  -ProcessExternalMeetingMessages $true `
  -AllBookInPolicy $true `
  -AllRequestInPolicy $false `
  -AllRequestOutOfPolicy $false
```

The key parameters are:

- **`-AutomateProcessing AutoAccept`** — invites are accepted automatically,
removing the need for a delegate to accept them.

- **`-ProcessExternalMeetingMessages $true`** — the critical one. It allows the
resource to accept invites from senders outside the tenant, which Cronofy's
invites are. This is `$false` by default.

- **`-AllBookInPolicy $true`** and **`-AllRequestInPolicy $false`** — everyone is
treated as a "book in policy" user, so requests are accepted outright rather
than forwarded to a delegate.

- **`-AllowConflicts`** — set `$false` to reject double-bookings, or `$true` to
accept every invite regardless of conflicts.

### Result
With this configuration in place, inviting an Office 365 resource calendar's email address as
an attendee on a Free/Busy event will be added to the calendar and the resource
will auto-accept the booking.

> **INFO:** Please contact [support@cronofy.com](mailto:support@cronofy.com) if you have any
problems with this configuration.



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