Hi John, I have everything configured pretty much as you describe except the DNSs in the External NIC of ISA. Mine are not blank but contain External DNSs... and everything works fine. What is the advantage of having these blank? Thanks, Kelli -----Original Message----- From: John Tolmachoff (Lists) [mailto:johnlist@xxxxxxxxxxxxxxxxxxx] Sent: Tuesday, May 20, 2003 10:58 AM To: [ExchangeList] Subject: [exchangelist] RE: Unable to send messages out of exchange http://www.MSExchange.org/ > Domain Controller- with an internal ip and dns itself. > Exchange Server - internal ip which is a natted ip and in the primary dns > we have the dns of the isp and in the alternate dns we have the dns of our > domain controller. > ISA server - its has an internal ip and has both primary as well as > alternate dns as public dns. There is a big part of your problem, DNS. Any computer on an internal network that is part of a AD domain MUST have as its DNS servers the internal DNS server ONLY. This includes the Exchange server and the Internal NIC of ISA. The External NIC of ISA should have the DNS server configuration blank. John Tolmachoff MCSE CSSA Engineer/Consultant eServices For You www.eservicesforyou.com ------------------------------------------------------ List Archives: http://www.webelists.com/cgi/lyris.pl?enter=exchangelist Exchange Newsletters: http://www.msexchange.org/pages/newsletter.asp Exchange FAQ: http://www.msexchange.org/pages/larticle.asp?type=FAQ ------------------------------------------------------ ISA Server Resource Site: http://www.isaserver.org Windows Security Resource Site: http://www.windowsecurity.com/ Windows 2000/NT Fax Solutions: http://www.ntfaxfaq.com ------------------------------------------------------ You are currently subscribed to this MSExchange.org Discussion List as: kirwin@xxxxxxxxxxxxxxxxxxxxxx To unsubscribe send a blank email to $subst('Email.Unsub')