Exchange Hybrid Server Concerns

[Curious_Kevin16]

One of the customers have a single Exchange 2016 server which runs on Windows Server 2012 and planning to go Hybrid (2016 Hybrid requires minimum of Windows Server 2012 R2). The challenge here is, its on Windows Server 2012 which apparently isn't supported to be a Hybrid server. They don't  want to have a second server as Hybrid either. 

As in-place upgrading the current server isn't a good idea, what are the best options here with minimum on-premise footprint ?

[#2]

Seeing Windows Server 2012/R2 is out of support in a couple of months, the best option is to install Exchange Server 2019 on Windows Server 2022 and migrate all Exchange services and mailboxes to that server and run the hybrid from there (then decommission the Exchange Server 2016 server). This gives the customer the longest window of supportability for both Windows Server and Exchange

[#3]

Thanks heaps @Dan Snape for the prompt response!

As the plan is to decomm the Hyrbrid in a couple months time up on stabilizing the 365 world, I was thinking if that effort worth it!

I'm more convinced towards spinning up a new server as a dedicated Hybrid server (in addition to the current one) which would be easy to setup and less risky. What you think?

Thanks again !!
Kev

[#4]

A second server would be an easier way to go. You'll need to configure your network to make sure Exchange Online can connect directly to the new server, and this might need a new DNS namespace and SSL certificate depending on your setup. Once all the mailboxes are migrated you can decommission the old server.
A few things to think about...Microsoft only support using Exchange tools to manage mail related attributes on-premises, so you need an on-prem server to comply with this. The exception is for Exchange Server 2019, where you can remove the hybrid server, but you must use PowerShell to manage the attributes (no GUI is available). Also, you get a free Exchange license for hybrid servers to help with complying with the above (you will still need an OS license). This is good if you have no mailboxes present on the hybrid server

[#5]

@Dan Snape,

Thanks for this! in terms of recipient management (mail related attributes) - I assume we can continue to use "Active Directory User and Groups UI" given that we will continue to have AD Connect Running ? are there specific attributes that are limited to PowerShell only?

Cheers!!

[#6]

No one will stop you using ADUC, but Microsoft don't support using it for editing mail related attributes. This is because ADUC (and ADSIEdit) does not perform any error checking for these attributes, so you could end up with inconsistent, invalid or duplicate values.

[#7]

Thank you Dan ! Appreciate the very quick turnaround and detailed information !

Cheers
Kev