I am in the process of a cross-forest exchange migration and need some advice about internal and external URLs.
My source server is Exchange 2007 sp1 rollup 10 in a Windows Server 2008 SP2 server which is the primary domain controller with FSMO roles for the source domain; sourcedomain.org. The external and internal URLs are set to mail.sourcedomain.org and the email addresses are user@sourcedomain.org.
My target server is Exchange 2013 in a Windows Server 2012 joined to targetdomain.net
I would like to keep the internal and external URLs as mail.sourcedomain.org because a lot of our users use the Outlook Web App and also to be consistent with the email addresses which will still be the same; user@sourcedomain.org
I tested that configuration and it worked fine but I had to edit the hosts file on the test computer to point mail.sourcedomain.org to the ip address of mail.targetdomain.net.
I would like to create a dns record to do this for me. I tried creating a cname under the targetdomain.net dns zone but the end result is mail.sourcedomain.org.targetdomain.net
Any advice on how to do this?