How to block webmail based chat clients?

[Saleem]

Hi,
I've posted some messages regarding this and ended up in nothing. Let me make it simple. I want to block webmail based chat clients (Google's chat inside gmail, Yahoo's chat inside yahoo mail)

I've already blocked them in protocol control and in intrusion prevention. So people who uses messengers or try to use with http were blocked.

However I am unable to block those people who uses it in webmail. For example, Gmail has https support throughout the session and people were able to chat in that inbuilt chat applet. Even though the event log of Intrusion prevention shows it is blocked, it is not actually blocked.

Since it is https i guess the signature based block in intrusion prevention fails.

Any idea how to get this working?

[jking]

The best way to do this is via web filter, just add the url of the web messenger (i.e. webmessenger.yahoo.com) on the url blocklist and it will deny all access to those sites. You may turn on logging too so you can review whose been trying to access those site ;)