Allowing some internal users to forward through Exchange 2003 SP2
Posted on 2006-06-13
We have an Exchange 2003 SP2 cluster with FrontEnd / BackEnd design. We are converting our internal users from a Netware 4.11 / NT 4 domain to W2K3 AD. Our current e-mail is a AIX 4.3 Sendmail (very prehistoric!). Basically I use the AIX Sendamil and Alias entries to transistion the users to Exchange. When the cutover is complete, I will update the DNS MX records to point to the Exchange 2003 server rather than the AIX Sendmail.
But here is my dilemma....
Our new W2K3 domain is ABC and the DNS is ABC.org. All the users are being defined to the new ABC AD and have email mailbaoxes as jdoe@ABC.org. There are few business units that have external business domains (XYZ.com) and ISPs that handle their mail (jdoe@XYZ.com). The AIX Sendmail allows the internal user to send mail out because it does not care about Windows Domains. However the users are part of ABC AD Domain and nneed to access the applications and servers in this DOMAIN. Since Exchange is so tightly intergrated will not let these users send mail as "jdoe@XYZ.com". In the Sendmail alias file, the user's ABC.org ID is directly forwarded to the XYZ.com id. Basically, they POP that XYZ mail server. So the issue is Sending through Exchange 2003 in the ABC Active Directory Domain (ABC.org DNS) as jdoe@XYZ.com.
The number of users that are like this are very small...so I do not want to add a convoluted solution or allow an open relay / spamming.
I have read about setting up Virtual Servers, Directories , Contacts etc. While it seems to be a straightforward idea, it is not clear what should work and not confuse the people needing to support the solution.