Automatically remove cancelled meetings from your calendar:

When a meeting gets cancelled, it will either be automatically removed from your calendar or automatically marked as cancelled (you decide which). The cancellation notice will not come to your Inbox. One really great perk of this is that it keeps your free time up-to-date, but you don't have to keep an eye on your Inbox for cancellations. People looking for your availability will see the newly freed-up time.

To set this preference, follow these steps:
1. Click File > Preferences, and then click Calendar and To Do.
2. Click the Display tab (if it is not already open), and then click the Views tab.
3. Select "Process cancelled meetings automatically," and then select whether to remove cancelled meetings from your calendar, or to show them as cancelled in the calendar