Dear All,I need some help related to my title:I have in my company local domain let me called (dom.local) connecting to isa server and this isa server has on his external NIC private ip(192.168.1.3) and this isa server connecting to internet through cisco router configure to Enable NATTING (to outside).also we have an external domain have the same name as internal domain let me called (dom.com) and mail system hosting in external company and this domain and mail system based on Unix.Now how can Ipoint my local exchange 2007to the external domain (Unix based on), and how to configure my localDNS(MX record) to send and recieve external E-mails, andtell me if I need to publish local Exchange while the external NIC of isa server has privte IP address.I try to think in this problem and this what I get:first we can remove the privte IP address from external NIC of isa server and replace it with public ip and disable NATTING in cisco routeralso create primery zone (dom.com) and in this primary zone creat A record point on public ip address of isa server external NIC and create MX record and pointing to the A record. in exchange 2007 adding dom.com as (New Accepted Domain).

Please see the posts in this thread Managing Accepted DomainsJames Luo TechNet Subscriber Support (http://technet.microsoft.com/en-us/subscriptions/ms788697.aspx) If you have any feedback on our support, please contact tngfb@microsoft.com

Hi James-Luothis is not the main idea behind my question, I need some help according to how in this case to configure Local DNS (not registered DNS) to send and recieve External E-mails while I have External domain hosting in external companyThanks alot

So, its not to send mails to other external domains, but use external domain (dom.com) to send and receive the messages for your domain Whats the exchange topology, single box? The MX record has to be recorded in a public DNS server, please see the Prerequisites section in this article (Its applied for exchange 2010, but prerequisites is same) For outbound mail flow, mails have to be sent to UNIX domain at first, and then let UNIX mail system to deliver the messages, the smart host has to be set in the send connector of exchange server, and so outbound mails can be routed to UNIX mail system. Of course, the configuration must be set on the UNIX mail system as well, so the inbound mails for your domain can be routed to your exchange users And the mail address should be set the dom.com as primary one, so that the external domains know where to send the messagesJames Luo TechNet Subscriber Support (http://technet.microsoft.com/en-us/subscriptions/ms788697.aspx) If you have any feedback on our support, please contact tngfb@microsoft.com

thanks alot for your Cooperationso if I understand you, I must pay for registered domain at first (replace dom.local to dom.com) to holding MX record. Even if the configuration must be set on UNIX mail system.if so I don't need the UNIX mail system and makemy own microsoft exchange mail system.

I havent said it very clear. If you use UNIX domain to relay the mail flow for your domain, the MX record of UNIX domain will be used, so you dont add another MX record James Luo TechNet Subscriber Support (http://technet.microsoft.com/en-us/subscriptions/ms788697.aspx) If you have any feedback on our support, please contact tngfb@microsoft.com