Office 365 & FOPE File Extension Exclusion Dictionary
I'm attempting to lock down our SPAM and Firewall settings with Office 365 and FOPE. One of the key things we want to do is prevent certain file formats from both entering and leaving our organization. This is often a common request among E-Mail security people. FOPE allows you to define all sorts of rules using Regular Expressions (RegEx) or using Dictionaries. Dictionaries are simply large CSV (Comma Separated Value) files that contain all of the extensions to be blocked.
The FOPE Admin guide provides a good starting list to build a dictionary. It's pretty hard to use RegEx for file extensions, if not impossible. I'm providing the CSV file we used to secure the system. It's a pretty good starting point and covers most files that can execute on a Windows box. We also included some of the OSX extensions that can execute as well, although this was not our primary goal since we have 1 Mac using the service.
For more details on uploading and defining policies take a look at the FOPE Best Practice Guide: http://technet.microsoft.com/en-us/library/ff715282.aspx
Brent
