We have an issue within an Office 365 Hybrid environment, where we are unable to remove/overwrite the Microsoft Online Email Routing Address (username@<domain>.onmicrosoft.com) for a user that has had a name change.
Within ADSI edit, the Microsoft Online Email Routing Address entry contains the new entry, however, within Azure AD and Exchange Online, it has created the new address alongside the old one:
I cannot remove the old entry directly from Azure AD/Exchange Online as all changes have to be made on-prem.
To make matters worse, another user has started with the same name as the old name of the other user, resulting sync conflicts.
Is there any way to remove the old @<domain>.onmicrosoft.com address? Any help would be greatly appreciated.
Cheers in advance.