I am looking to move my small business off of POP email to something hosted. I have looked at Google Apps for Business and Office 365 but one crucial roadblock remains unanswered:
How can I restrict access to the services so that they are only available from within the office?
Just like how our current POP system works, I just want the employees to be able to access their email from within the office during work hours. Moving everything online opens the door to information leakage, and we can't have that.
I have found nothing for Office 365 and I have only found gControl for Google Apps, but it costs more per user than Google Apps itself. I also have no experience with SSO solutions (this is a really small business).