Consider the following scenario in Office 365:
- You have the following domains:Contoso.onmicrosoft.com
- AUContoso.com and UKContoso.com are accepted domains that were added to the Hybrid Configuration wizard. Contoso.com is federated and can't be set as the default accepted domain in Office 365. Therefore, contoso.onmicrosoft.com shows as the default domain.
To resolve this problem, change the email address of the site mailbox. To do this, follow these steps:
- Connect to Exchange Online by using remote PowerShell. For more information, see Connect to Exchange Online using remote PowerShell.
- Run the following command:
Set-Mailbox -Identity MySiteMailbox1 -EmailAddresses SMTP:MySiteMailbox1@contoso.com, smtp:MySiteMailbox1@aucontoso.com -EmailAddressPolicyEnabled:$False
Article ID: 3172620 - Last Review: Dec 29, 2016 - Revision: 1
Microsoft Exchange Online