We are anticipating upgrading from 2012 to 2014 R2 in the next month or so. I thought I would try a dry run with cloned VMs with host1 NIC settings (VMware). We are a secondary domain with 4 Post Offices (our MTA & 1 of the POs share a server).

Our 4 servers (MTA&PO1, PO2, PO3, & PO4) are all Windows 2008 R2 servers. Our eDirectory is still running on an old NW 6.5 box (8.73) and we only use it for the GroupWise authentication (my goal is to switch to Active Directory for authentication and drop eDir). I upgraded the cloned Windows servers to 2012R2 and I was able to test send email between POs just fine (GW 2012). I upgraded our domain and post office agents to 2014 R2 and they can still send email but only on the same PO as the MTA no longer runs. I should add that I am running the 2014 R 2 install without a service pack (waiting to get those - long story).

Creating a new server with MTA and PO and the MTA agent runs fine, the MTA just didn't like the upgrade.

Questions:

Does 2014 R2 (or the upgrade process) require access to the Primary domain for the MTA to run (2012 didn't have that requirement)?
Will I be able to associate the users with AD without the need to upgrade our aging eDir from 8.7.3 to 8.8 to x.x as part of the process?

Thanks,

Eric