Hi, > Exchange needs port 135, as an RPC port. Using ISA server allows opening > this port securely. So if I installed ISA server and opened up this port, tnen my clients would still need to open port 135 at their end right? I very much doubt if I could convince any clients to open up those ports at their end through their firewalls, even to my dedicated IP addresses. Also, I seem to recall there are other companies offering these services that do not require their clients to open up port 135 etc. best regards Mike