When configuring the filtering of instant messaging traffic that is going on under the Windows Live Messenger protocol, the following is useful to know.
The host name of the instant messaging server is messenger.hotmail.com. This is the host name that must be resolved in a redirecting rule by the IP address of an appliance with an instant messaging proxy.
Sometimes a client connects to the server without requesting the host name to be resolved in a DNS lookup. In this case, it can help to find and remove the following registry entry within the client settings:
For a successful logon to a server, the following URL must be accessible to a client without authentication:
For this reason, you need to insert this URL in the whitelists that are used by the implemented web filtering rules on an appliance.