Block MSN Messenger in Content Type of ISA 2004
By Gustavo Robles Fonseca

To block MSN messenger using ISA 2004 firewalls, you need make an access rule that permits all content type if you wish, or permit only the content that you like.

The first step are make a new content type.

In the toolbox select Content type and new:

In the New content type set, edit the name and description that you like, in available types, type: application/x-msn-messenger and Add. And click OK.

When this is ready you need make an Access Rule if you wish open Internet through ISA to your users, and also block IM communications.

Create the Access Rule, with the protocols that you want and the specific user if you want. After you make the Access Rule, double click in the rule an go to the tab Content Types tab and select selected content types…… in the Content types box select the content that you want permit, in this case all except MSN Messenger, an click OK

After this all ready and you apply the firewall policy, your users will not be able to connect to MSN Messenger 7.0 above through the ISA firewall.

Conclusion:

In the same rule it can be done, permit access to internet and block the IM that no are permitted. Remember block the site webmessenger.msn.com –Gustavo Robles Fonseca