Forum Discussion

Brass Contributor

Jul 12, 2018

Enable AD Connect sync with existing Office 365 accounts and mailbox

Hi, I'm managing an Office 365 tenant with 60 users with E3 subscription. For the moment all users have a username with @mydomain.onmicrosoft.com domain and a mailbox associated. Now, I want ...

MVP

Jul 24, 2018

Hi Julien,

It doesn't matter what the UPN is, as long as it matches the user's login name. Or are you saying that your on-premises UPN is not an email address, i.e. username@domain.local? If so, when configuring Azure AD connect, just select to use mail attribute for UPN and you should be fine.

You do not need Exchange to convert users to shared mailboxes, you can do that in Office 365 too. Last time I installed an Exchange server from scratch, it took 10 hours or so. How difficult it is, depends on your current environment etc.

Dominik Hoefling

MVP

Aug 01, 2018

Hi Julien,

1. You NEED Exchange on-premises for recipient management. It is not supported to change for example alias and proxyaddresses attribute via Active Directory.

2. Only with Exchange 2016 CU10 you can create shared mailboxes directly in Exchange Online.

3. Your UPN should match your primary smtp address as best practices. If you can do this change, do it.

Best,

Dominik

jhathcock
Copper Contributor
Mar 19, 2019
Dominik Hoefling You don't need a full install of Exchange to manage a hybrid AD / O365 mail environment. You just need the Azure AD Connect software. It includes the PowerShell modules needed for AD Users and Computers to edit the necessary information.