Newly Added Domains To An Office 365 Tenant Are Not Visible In Set UPN Dropdown Menu
A new domain is added to the Office 365 tenant after the migration pair has been created in Migration Manager for Active Directory Office 365. When I go to set the UPN of a new collection the newly added domain name is not present in the drop down list.
When the initial migration pair is created the approved domains list is pulled from the Office 365 tenant. Once the list has been pulled it is static and you're no longer able to modify the list of domains from Office 365.
In order to show newly added domains in Office 365 to "Set UPN" drop down list you will need to delete the migration pair and create a brand new one. This will pull a new list of Office 365 domains.