AADconnect with Exchange server but without Hybrid Config - Managing users

Copper Contributor


We have all of our mailboxes in Exchange Online. MX records point to Exchange Online. Autodiscover points to Exchange Online (autodiscover.outlook.com).

These were migrated to O365 from a previous project (previous supplier).


I have a new on-premises Active Directory forest. I have configured AADConnect server and will be syncing my new AD users to Azure.


I will also be hard matching the Exchange Online mailboxes to my on-premises AD users (using immutableID command. Not an issue).


As I have installed a new Exchange 2016 environment, I want to see the Exchange Online mailboxes visible in my on-premise Exchange ECP.


I want to do this without having to set up a Hybrid Configuration. The reason is, There is no need for Free/Busy, no need for mail to route across on-prem and EXO - because, Autodiscover points to Outlook.com, MX records point direct to Exchange Online.


I just want to be able to see the Exchange Online mailboxes displayed as "Office 365" mailboxes in my on-premise Exchange 2016 so IT admin team can do BAU activities such as changing Exchange related attributes (e.g. hide from address list) etc from on-prem. Or even be able to create a new remote mailbox from Exchange on-prem.



4 Replies

Hey @LIT-RS,

You should be able to use below cmdlet :-

Enable-RemoteMailbox samaccountname -Remoteroutingaddress alias@domain.com

This should allow you to see the mailbox in on-prem console as a Remote Mailbox. Hybrid is not required to run this cmdlet.

I'd recommend to test this with a  test user first.



Hi Deepak @DeepakRandhawa , thanks for this.
I guess I need to run this on each individual mailbox individually? This is just to see the Existing O365 mailboxes in my ECP, correct?
I read somewhere that we’d also need to set-mailuser ? Is that irrelevant then?

To create new mailboxes in o365, as we’re using AADconnect, how would we go by that to create in from on-prem as O365 mailbox? Would we use the same command?

Hey @LIT-RS 


Yes, this need to be run for each mailbox.
Yes, this is to see existing O365 mailboxes in on-premises ECP.

Not sure what you read about Set-MailUser, I think it is irrelevant in this context.

You can follow the same process that you have been following till now to create new mailboxes and then run this command for each new mailbox that you create.



Deepak is correct with the "Enable-RemoteMailbox" command as this will mail enable your on-prem user accounts and update their recipient types. I would also recommend running the hybrid config wizard as it will add the remote routing addresses into your email address policy and also enable the "New Office 365 mailbox" button in the ECP/recipients page to allow you to use the Exchange wizard to create local AD accounts, and following the next AD Connect sync operation, will create the Exchange Online mailboxes for them.