How can I test Calendar Sync for Office 365 in my Sandbox?
Our recommendation is to test Calendar Sync in a Salesforce Developer org. To get a free Developer license from Salesforce, please go to http://developer.salesforce.com/
How do I authorize my Office 365 account when Calendar Sync encounters a problem?
If you received an email with the subject "Cirrus Insight Calendar Sync Problem," that means Calendar Sync wasn't able to access your calendar and you'll need to grant authorization.