Hi, > To be able to connect to a Microsoft Exchange Server in that way, the > firewall has to have a number of ports open. However, the absolute best way > is to use ISA server as the firewall, as that is application aware and > allows to easily "publish" Exchange securely, as opposed to just opening > ports. I have all the ports open that are listed in the following article but that does not seem to be enough. I have also tried opening all ports. http://support.microsoft.com/default.aspx?scid=kb;en-us;278339 I do have ports 135,137,138,139 and 445 blocked at the router and the option of opening them up does not exist, nor does the option of using the ISA server. These are the "netbios traffic" ports. Can MS Exchange Server work without having to open up these ports? best regards Mike