Here is for all IPs:
acl ms-messenger req_mime_type -i x-msn-messenger
acl msn-messenger req_header User-Agent -i msn[[:space:]]messenger
http_access deny ms-messenger
http_access deny msn-messenger
Received on Wed Mar 01 2006 - 17:58:00 MST
This archive was generated by hypermail pre-2.1.9 : Sat Apr 01 2006 - 12:00:03 MST