Microsoft Office 365 Beta and Forefront Online Protection for Exchange

This documentation, Overview of Complex FOPE Mail Flow Scenarios, can be helpful if you use FOPE and are planning to bring a subset of your mailboxes to the cloud, but you also keep mailboxes on premises. It addresses a handful of cross-premises scenarios that you may run into. I will throw in the caveat that it's beta documentation. Feel free to comment on it and help us improve it.