Hi! Here's my problem: I have installed and configured Exchange 2007, everything works fine, with exception of webmail. Namely, when I am accessing mailboxes from INSIDE my company via webmail, everything works fine, but from outside it just won't work. The problem is probably somewhere on the ISA server, but I just can't figure it out. Any ideas?

What version of ISA and are you using a single or multiple NIC config? how many, what networks, what rules? Exchange 2007 CAS server also had a published URL option which needs to be set for the OWA website on the CAS Server. EMC > Servers > CAS > CasServer > OWA Properties This is the public url you plan on publishing your owa to, e.g. webmail.company.com Also be sure to specify that secure connections are to be used all round on your ISA publishing rule. If it is a single nic ISA config, you need to add a host entry for webmail.company.com to map to the internal IP of the CAS server and tell the publishing rule to redirect all requests for webmail.company.com to webmail.company.com. this means that the request will come in for the site, then be redirected (using the hosts entry) to the internal server on the same site name.