This is very similar to a recent question I asked, but I can't quite get the solution to work at a similar site where we're adding an exchange server to a network with a Netmail server. Here's what I have:
Two mail servers are internal to the organization. Public MX records point mail to a NetMail server. I'm adding an Exchange 2003 server for a few users. The server name is exchange. I've set the Netmail Server to forward undeliverable mail to exchange.domain.com.
I read through MS KB article http://support.microsoft.com/default.aspx?kbid=319759
although it says that it's for sending messages to contactw whose user accounts exist in Active Directlry but whose e-mail addresses point to a foreign messaging system that shares the same SMTP domain name space as the Exchange server. That's close, but I don't want to have to add all the users to Active Directory that are on the Netmail server. What I'd like to do is get the Exchange server just send all of it's mail directly to the Netmail server for resolution. Then, for the few addresses that are on Exchange instead of Netmail, Netmail should forward it to exchange (since it's undeliverable) which should receive and deliver it.
My first step was to add exchange.domain.com to the default recipient policy, but it said it wouldn't let me since exchange was a server name. So I added a DNS entry for mail2.domain.com and pointed it to the exchange server, then set the NetMail server to forward there. So I now have a single polidy, the default:
ticked SMTP @mail2.domain.com (bold for default)
ticked smtp @comain.com - not set as responsible for all mail to this domain
tickex X400 - default stuff here
I also added a connector called "netmail connector" and set it to forward all mail through this connector to the smart host: <ip address of my Netmail server> and added EXCHANGE under the local bridgeheads. Under address space, I added precisionservice.com.
Well, none of this worked.
* from the outside I get "Delivery to the following recipients failed email@example.com.
* from the inside (from a Netmail account) - nothing -- no delivery, no bounce message
Exchange users can send to accounts on the Netmail server (firstname.lastname@example.org) and to outside addresses without problem.
I'm still missing something. That KB article had info on adding @local as a domain. Is that part of this puzzle?
Also, when making changes in this area of Exchange I've been stopping and starting the services for Exchange Routing Service and the SMTP service. Is that correct, or are there other steps?
I'm also leaving the users on exchange with an email address of email@example.com (not firstname.lastname@example.org).