Error when changing domain foer certain groups, but not all gvroups

Question

We're changing the domain for Office 365 users and groups to a new domain. (When I say "new," the domain has been in our DNS records for a month or so.) Of the 59 groups I've changed, I'm left with 6 that refuse to change. With these 6 groups -- trying one at a time --I get the error:

We couldn't change the domain for 1 group. This might be because an email alias you're creating for a group already exists. Refresh the list of groups and try changing them to a different domain. If you recently edited or deleted an email address, allow 1 hour for the change to take effect. ‎Go to your Active teams & groups list‎ to delete the groups if you continue to see this error.

None of these groups shows an alias in the alias column, but , when looked at under Groups, they do have onmicorosft.com aliases. And, if I try to remove the alias, I get the error:

Your group must have at least one email address or alias that uses the xxxxxxxxxx.onmicrosoft.com domain so it can continue to receive email if there are issues with its other domains.

Is there a way out of this Catch-22?

Thanks,

Dave

Answer 1

Dear Dave,

Many thanks for your kind response,

Based on the description you have provided, since Microsoft 365 group has mailbox, The fallback domain (xxx.onmicrosoft.com) cannot be removed. At least one alias is needed for routing within O365 ecosystem. You can refer to Add and replace your onmicrosoft.com fallback domain in Microsoft 365 - Microsoft 365 admin | Microsoft Learn.

Therefore, kindly try to add a custom domain as the primary address for the group with a different alias. For example, if you have the alias failing with alias@domain.onmicrosoft.com, try to use ******@domain.com instead and check if the issue persists. you can also check who has the alias using via PowerShell. To check this, you can run the command below:

Ignore steps 1-3 if you already installed the Exchange Online PowerShell module and just connect (step 4). Run Windows PowerShell as an administrator and input the following. Ref: Connect-ExchangeOnline (ExchangePowerShell) | Microsoft Learn

1. Set-ExecutionPolicy RemoteSigned
2. Install-Module -Name ExchangeOnlineManagement
3. Import-Module ExchangeOnlineManagement
4. Connect-ExchangeOnline #sign in with your admin account credentials.
5. Get-Recipient <enter affected alias address> -resultSize Unlimited

I look forward to your update. Please feel free to let me know how it goes or if I got you wrong. If you still have any concerns, please let me know so I can provide more suggestions. 

Thank you for your precious time. Have a nice day.Sincerely,Libeamlak | Microsoft Community Moderator

Answer 2

Hi - Thanks for your response.

All groups are type "Microsoft 365 group."

I'm using the Admin center, so going to Settings>Domains

The new domain is not the onmicrosoft default. Note that many users and many other groups have converted OK despite the fact. And we are not eliminating the default domain.

I'm not sure I understand when you say "associated in SharePoint." But I went to Identity and looked up each group. Of the 5 groups that won't let mew change their domain, 3 of them show a link to SharePoint, but 2 do not.

Thanks,

Dave

Answer 3

Dear Dave,

Good day! Thank you for posting to Microsoft Community.

Based on your description, I understand that you’re encountering an issue while changing the domain for groups. Specifically, you’re getting an error related to email aliases. The error indicates that the aliases that correspond to the domain for all mail-licensed users and for all mail-enabled groups aren't removed or there is still associated alias with the same account. So that, Microsoft 365 blocks the move/change of a domain until the aliases that correspond to the domain are removed.

Therefore, in order to understand your query and provide possible solutions, May I please double confirm if the group type in question? is it a Microsoft 365 group, Distribution group, Dynamic Distribution group or mail-enabled security group?

• May I please double confirm if you used PowerShell or Microsoft 365 admin center to change the domains?
• May I please double confirm if the new domain is the default domain in your organization or onmicrosoft.com in the admin center? if you haven't check it yet, kindly sign in to Microsoft admin --> Settings -->Domain, then check if the new domain is a default domain for your organization.
• If it is a Microsoft 365 group, may I please double confirm if these group accounts in question are associated in SharePoint?

I look forward to your response. Kindly note that the above requested information is required for further analysis and troubleshooting of your situation. Your patience and cooperation are much appreciated.  Thank you for your precious time. Have a nice day.Sincerely,Libeamlak | Microsoft Community Moderator