Forum Discussion
Local domain mailbox migration error
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).
I know that, but I'm talking about the "AD internal domain" which is by default added to all exchange users created.
Each user has his primary SMTP address as user @ domain.com which is the public domain and an alias pointing to the AD domain domain.local.
We made several migration and never happened that the internal AD domain was rejected during the migration
It's only added by default becasue you have the .local address in your email address policy. Update the email address policy to remove the .local address, then you'll need to run a script to remove the .local address as an alias from all existing accounts (removing the .local address from the address policy will not remove it from existing objects, it just means any new objects will not have the .local address).
that's correct, I know that it's the default policy managing the domain.local address and that I can remove it to solve the issue.
My point is that in all other situations where I had the same configuration, I did not have such issue while migrating mailboxes to O365 in hybrid environment and cannot understand it
if I remove the domain.local alias I can successfully migrate the mailbox
