Switch default domain in Office365
Posted on 2016-10-26
We have an Office365 tenant testTenant.onmicrosoft.com.
There are some users that have licenses for Office Online and Exchange Online.
Those user names are as follows:
The users habe One Note books and files.
Now we added our custom domain test.de zu the Office 365 tenant and verified it.
We also have a on Premise AD domain "test.de" which is connected to the Office 365 tenant with AAD Connect and Standard-Settings.
What happens now:
- We create a user in on premise Active Directory.
- We set the Attributes "proxyAddresses" and "mailNickname":
- proxyAddresses: SMTP:firstname.lastname@example.org
- mailNickname: user.name
- Now we sync the AD to Azure AD (AADConnect
- The user is created in Azure AD as email@example.com
- As soon as I add the license for Exchange Online the mailbox gets created.
- The user then has following e-Mail-Addresses:
That`s fine and what I want.
Now I saw, that the configured default Domain ist still "testTenant.onmicrosoft.com".
What exactly does that mean?
We are planning to put the MX record for test.de to Office 365 in the future. Would it be a problem that the default domain is still testTenant.onmicrosoft.com?
What would happen, if I change the default domain to "test.de"?
- Will the old users (user.name@testTenant.onmicrsofot.com) stay untouched? (user-Login-Name, E-Mail-Addresses, user data)
- Which E-Mail-Addresses would new users get, when I enable the Exchange Online license? (Only @test.de or also testTenant@onmicrosoft.com too)
What would you prefer? Switching the default domain?
The goal is to delete all the old testTenant.onmicrosoft.com Accounts after our migration is done.
Man thanks in advance!