We are currently in the beginnings of a migration from Exchange 2010 SP3 CU7 to Exchange 2013 CU6 (not yet installed) and have a question about the need for disjoint namespace.
With our current setup, we use the internal DNS name of internal.contoso.com.au, and the external DNS name of contoso.com.au. Cnames are pointing mail.contoso.com.au to the mail.internal.contoso.com.au host.
This setup allows us to use mail.contoso.com.au both internally and externally (on the internet).
Do I still need to use a disjoint namespace when our current system works? I just can't see any benefits of pushing out more GPO settings etc, when this simple method (at the moment) seems to work.
Thank you very much for your assistance.
Cross post here: https://social.technet.microsoft.com/Forums/office/en-US/8a78ff85-cc99-449a-9190-e296ddeec553/do-i-really-need-disjoint-namespace?forum=exchangesvrdeploy#8a78ff85-cc99-449a-9190-e296ddeec553