Forum Discussion
Local domain mailbox migration error
I ran into an issue while migrating from on-premise to O365. On-premise AD domain is “domain.local” so users have their mailboxes smtp address as follows: primary smtp mailto:email address removed ...
The domain.local format is not supported in the online environment.
Only officially purchased domains are supported.
You must add a public domain(UPN suffix) in the Active Directory Domains and Trusts console and then change all user accounts to the public domain(UPN suffix).