How do I switch the email name syntax in an on-premises enviroment while preserving emailname compatiblity?

Question

I want to switch from an email/name syntax like:

[e-mail] to [e-mail]

I also need to make sure that people are able to reach them with their old email adress/name.

Is there some kind of build policy based on the domain controller?

Up-to-date Windows server versions here. We are unfortunately using romain profiles. Owa is used as well (Exchange 365).

Answer 1

Exchange 365, did you mean Office 365/Exchange Online? For cloud-only Office 365 organizations, bulk email address changes can be made when adding a new domain to your tenant, or at any time you can bulk add SMTP addresses to multiple mailboxes using PowerShell.