Do anyone here use user certificate authentication at the ISA firewall's Web listener? If so, how do you scale the solution? The process of obtaining the user certificates and then mapping them in the Active Directory as described at http://www.microsoft.com/technet/prodtechnol/isa/2004/plan/owaclient.msp x is extremely admin intensive work. Thanks! Tom Thomas W Shinder, M.D. Site: www.isaserver.org <http://www.isaserver.org/> Blog: http://spaces.msn.com/members/drisa/ Book: http://tinyurl.com/3xqb7 <http://tinyurl.com/3xqb7> MVP -- ISA Firewalls