Forum Discussion
Shared mailbox in Secondary Domain creates user with Primary Domain
Hi,
We have multiple domains in a single Office 365 tenant:
- PrimaryDomain.com (Default domain in O365 Admin Portal => Setup => Domains)
- domain2.com
- domain3.com
Whenever, I create a shared mailbox or user in a secondary domain, it automatically creates a username/alias with PrimaryDomain.com.
Examples of the issue (current):
- When a shared mailbox info@domain2.com is created, info@PrimaryDomain.com becomes its alias. And also, what's worse is that info@PrimaryDomain.com becomes a user in Users => Active Users tab of Office 365 Admin Portal and info@domain2.com is nowhere to be seen in the Users tab (no even as an alias).
- When a user mailbox is name@domain2.com is created, name@PrimaryDomain.com becomes its alias.
What we want:
- When a shared mailbox info@domain2.com is created, info@domain2.com is the only alias. And also, info@domain2.com is a user in Users => Active Users tab of Office 365 Admin Portal.
- When a user mailbox is name@domain2.com is created, name@domain2.com is the only alias.
How can this issue be resolved?
Thanks,
7 Replies
I just ran across this today.... FIVE YEARS AFTER YOUR POST. lol
It's absolutely bizarre.
So if you setup a shared mailbox using sharedgroup @ any domain attached to the account, an alias is automatically setup for sharedgroup @ primary domain.Once this is done, you can no longer setup anything else with sharedgroup @ on ANY domain no matter how many you have as they all create this mystery alias in the background and fail because it's already created elsewhere.
If you add an additional alias it will allow you to delete the @primarydomain as an alias....you think you've solved it. But when you visit again you'll see that it's returned.
The fix mentioned above no longer works. Apparently MS "fixed" that and it no longer works. It reappears after you save just as if you didn't do anything at all.
Anyways, although the error says so, the problem is not because the domain being setup is in use elsewhere, it's because your boxname@ is in use by your primary domain.
If you have multiple domains you can normally duplicate users for each domain. But not on a shared mailbox. Once you do, regardless of the domain it's setup on, that username can no longer be used across all of the domains in the account.- I have now created the new users and licenced it. I have then converted to a shared mailbox and so far the alias has not been added for the primary domain.
- Also I noticed that the userid is in the primary domain and not the custom added domain.
- This exact same thing has happened to me for a client. Recently added a fourth domain and created shared mailboxes. Those shared mailboxes get the primary domain added as an alias. Deleted the alias using Exchange Admin Centre and then they return. Also an active user is created!
I am having the same issue.
Here is my solution to fix it.
1. Create new Shared Inbox mailto:email address removed for privacy reasons
(this will wrongly create a user and a shared inbox alias of mailto:email address removed for privacy reasons)2. Go to Users - Active Users and find mailto:email address removed for privacy reasons - edit the user and change the username to mailto:email address removed for privacy reasons
3. Go back to the Shared Inbox and delete the Alias.
Is the primary the tenant.onmicrosoft.com one? If so, the issue is due to the default Email Address Policy in ExO, which stamps @tenant.onmicrosoft.com to each object. You cannot modify that policy, however you can change the default domain.
- tenant.onmicrosoft.com is no longer the "Default" tenant in Office 365 Admin Portal => Setup => Domains.
Rather PrimaryDomain.com is the "Default" domain in O365 Admin Portal => Setup => Domains
So, that ExO EAP shouldn't apply right?
