Solved

Switch default domain in Office365

Posted on 2016-10-26
3
45 Views
Last Modified: 2016-10-26
Hi,

following situation:

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:

user.name@testTenant.onmicrsoft.com

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:user.name@test.de
   - mailNickname: user.name
- Now we sync the AD to Azure AD (AADConnect
   - The user is created in Azure AD as user.name@test.de
- As soon as I add the license for Exchange Online the mailbox gets created.
   - The user then has following e-Mail-Addresses:
     Primary: user.name@test.de
     Additional: user.name@testTEnant.onmicrosoft.com

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!
0
Comment
Question by:Systemadministration
3 Comments
 
LVL 39

Accepted Solution

by:
Vasil Michev (MVP) earned 500 total points
ID: 41860213
You can safely change the default domain, old users will not be impacted. New users will get both domains added as aliases.
1
 
LVL 14

Expert Comment

by:Todd Nelson
ID: 41860511
Why do you want to remove the *.onmicrosoft.com domain?

Review the "Renaming or removing the onmicrosoft.com domain" section in this article ... https://support.office.com/en-us/article/About-your-initial-onmicrosoft-com-domain-in-Office-365-b9fc3018-8844-43f3-8db1-1b3a8e9cfd5a?ui=en-US&rs=en-US&ad=US

If you can't remove the *.onmicrosoft.com domain there must be a reason behind why each user has a *.onmicrosoft.com email address associated with their account.  Do a bit more research to find out what the ramifications might be if you do remove it.  Contact support and ask them too.
0
 

Author Comment

by:Systemadministration
ID: 41860754
Hi,
I was able to change the default domain without problems.
I only had the re-configure the  AAd Connect tool.

Thanks!
0

Featured Post

U.S. Department of Agriculture and Acronis Access

With the new era of mobile computing, smartphones and tablets, wireless communications and cloud services, the USDA sought to take advantage of a mobilized workforce and the blurring lines between personal and corporate computing resources.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

This article explains in simple steps how to renew expiring Exchange Server Internal Transport Certificate.
Read this checklist to learn more about the 15 things you should never include in an email signature.
Microsoft Office Picture Manager has a Picture Shortcuts pane that shows a list with the Recently Browsed folders. While creating my video Micro Tutorial here at Experts Exchange showing How to Install Microsoft Office Picture Manager in Office 2013…
In this video I am going to show you how to back up and restore Office 365 mailboxes using CodeTwo Backup for Office 365. Learn more about the tool used in this video here: http://www.codetwo.com/backup-for-office-365/ (http://www.codetwo.com/ba…

910 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

25 Experts available now in Live!

Get 1:1 Help Now