Using Group Policy to control Outlook security/attachments behavio

[Adam]

Hope I'm in the right discussion group (apologies if not).
We have recently upgraded from Office 2003 to 2007. We are a single Windows
2003 domain organization using active directory. We've set up a group policy
object for our staff members. Under User Config/Admin Templates/Microsoft
Office Outlook 2007/Security/Securty Form Settings/Attachment Security we've
set the Display Level 1 Attachments setting to disabled to prevent users from
looking at dangerous attachments and we've set the Outlook Security Mode (in
Security Form Settings) to enabled and set it to use group policy. I've
looked up the Level 1 file types for attachments on the microsoft website and
ZIP files aren't listed so I expect the users to still be able to view ZIP
file attachments; however, this is not the case. Outlook is still blocking
ZIP files and I can't figure out why. Any thoughts?
Many thanks,
Adam

 

[Ken Slovak - [MVP - Outlook]]

Outlook doesn't block zip files unless they are added to Level1Add manually
or by policy or if the security form restricts them (same effect as using
Level1Add). It could also be some other type of software such as A-V or
firewall software that's blocking them. Do you see a message in the InfoBar
that Outlook actually blocked zips?

 

[Adam]

Ken,
Many thanks for your response. It is definitely Outlook blocking the ZIP
files (info bar displays: "Outlook has blocked the following potentailly
dangerous file attachament", etc). I've gone through all other GPO's that
apply to Staff and can find no entries under Outlook settings for Level1
attachments(in fact, none of the other GPO's has any Office settings
configured as we've placed all those settings in one GPO). Have checked
relevant registry hives for affected logged in users and see no keys or
values set for Level1. Definitely nothing to do with A-V as we've checked
that as well. We also run a network security software suite called Ranger
which we've gone over with a fine toothed comb and it isn't restricting email
in any way. At a complete loss as to where Outlook is picking up this
restriction.