Guest Tips 1: Outlook Extension blocking

A couple of Guest tips. 3 actually, these from a friend of mine, whose
Blog can be found here.

So without further Ado
Tip #1
Here is a little registry hack to allow .exe and .zip attachments in Outlook 
(if you really have to accept them, which the folks at Microsoft think 
you don't...)

Please make sure you have backed up your registry first. 
If you don't know how - please stop now! 

Using regedit or regedit32, or some other tool to edit the registry, browse to 
the following key:
HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\Outlook\Security\

Create a new String value called Level1remove and set the value = "exe;zip"

The reason this works:

Microsoft have built in two levels of attachment "protection" in Outlook. 
Level 1 (these files cannot be received) which consists of a whole load of 
dangerous file types; and Level 2 (these files must be downloaded to disk 
before opening) which has no extensions by default and is user configurable. 

Quite sensibly someone in Microsoft decided that to allow users to remove items
 from Level 1 would be silly. Obviously users are "clickers" and want to be able
 to receive everything and click on the virus payload if they so wish!

So, failsafes were built in:
Extensions on the Level 1 list will always be considered a threat 
(no matter what action is taken by user or administrator).

Level 1 cannot be modified through the front end.

A system administrator can (if (s)he knows how) demote Level 1 "threats" to 
Level 2 using the above registry key. This means that users will then be able to 
receive the attachments but will still not be able to just "click" them open. The
file must be saved to disk first. Any user who will go to the trouble of saving 
the attachment and opening it deserves what they get if it really is a threat.

You can include any extension in this string 
(as long as it is on Microsoft's Level 1 restrict list obviously).