log_messenger

[EDUARDO MARQUES]

Hi, i�m new around here and i�m looking for 
help.
I have a debian firewall for my local company, 
it has at all 12 people working here.
I want to make a log of all the information 
that go through the messenger. I want to see 
the ip machines and users that use the 
Messenger..to keep that information in some 
way, to see th trafic for that port. How can I 
do that? Where will my log file stored?
Thanks for your help.