Can I add existing AD groups to Exchange

Question

We are using an Office365 Hyrbid deployment with Exchange 2016 on premise. The Hybrid setup was deployed after our users and groups were created and synced from AD, so they do not currently appear in our Exchange server.

Is there any way to make these groups Exchange aware, without having to delete and recreate them from scratch?

With our mailboxes in Exchange Online, we had to run a New-RemoteMailbox command for each mailbox, so wonder if there is some way to manually populate the required attributes in these groups so they show in Exchange.

I suspect not possible though.

EDIT: I should point out that when we synced the groups, we had already populated the ProxyAddresses attribute, so that they appeared with the correct domain in 365. What we want is for these groups to now be manageable from our on premise Exchange server.

Solution

The solution to this was for me to convert our groups from Global to Universal types (Thanks to @user5870571 for turning me on to this initially), and then run a command in the Exchange management shell to mail enable the groups.

The command was:

Enable-DistributionGroup -Identity "Group Name" -PrimarySMTPAddress "[email protected]"

So simple if you know what commandlet to use.

Comments

[user5870571]

You want the AD groups to have email attributes for the on premise server or for Office365?

[James Edmonds]

Sorry my question is a little unclear. The groups have enough of their normal AD attributes populated so they sync to 365 and work using our primary domain as expected. What I need, is for the normal msExch* attributes to be populated in a way they would be if I created the group through Exchange in the first place.

[James Edmonds]

I think my question was a little unclear, as the above is what we have already been doing for the past year so the groups work with our domain in 365. This however does not make them Exchange aware, as the process does not include any of the msExch* attributes that Exchange populate when it creates the group. My scenario is Exchange Online knows about the group, Exchange on-premise doesn't.

[user5870571]

Are you creating the groups in Exchange Online or in AD?

[James Edmonds]

Groups are created in AD, then synced to 365.

[user5870571]

Why can't you create an email enabled group in AD (which by default should be on premise Exchange aware) and then add proxyAddress and do the dirsync so the group is seen in Office 365?

[James Edmonds]

If I create an AD distribution group, it does not automatically show up in Exchange. Unless I need to set it to Universal rather than global?

[James Edmonds]

Unfortunately it does not. I think it requires a lot more attributes to be populated, such as legacyExchangeDN and some of the msExch attributes.