You need to publish it for SMTP access if you want to receive email from the Internet. If it is for internal use only, you don't need to publish it. Look in here for "Configuring Protocol Rules to Support the Internal SMTP and DNS Servers" and the section right after that regarding "Configuring the SMTP Server Publishing Rule". http://www.isaserver.org/shinder/tutorials/isaserver_smtpsupport.htm Regards, Andrew -----Original Message----- From: Francois Conradie [mailto:francois@xxxxxxxxxxxxxx] I understand most of our network and the installation of ISA server on it, but I'm not sure about one thing: We have MS Exchange 5.5 on our network, it cannot be accessed by employees by means of dailup and is simply on our network. Do I have to publish it or will it work fine without publishing.