An absent feature from Exchange Online (Office 365) is email address policies, which are put to good use in on-premises Exchange deployments to automatically assign the desired email address format to mailbox users.

The lack of email address policies to date has presumably been due to challenges of implementing them safely in a multi-tenant environment such as Exchange Online. Without email address policies, customers need to run PowerShell scripts (like Add-SMTPaddresses.ps1) to update the email addresses for their cloud-only mailbox users. Customers running a hybrid configuration, or otherwise running directory synchronization, can still use email address policies to update email addresses for on-premises objects and let the changes synchronize to the cloud.

Email address policies were briefly visible in the Exchange Online admin center, but weren’t actually functional.


It seems the brief visibility of email address policies was in relation to changes to enable multi-domain support for Office 365 Groups, which makes use of email address policies but is managed via PowerShell.

About the Author

Paul Cunningham

Paul is a former Microsoft MVP for Office Apps and Services. He works as a consultant, writer, and trainer specializing in Office 365 and Exchange Server. Paul no longer writes for


  1. mhare

    I don’t believe this is in the admin portal any longer. Seems its likely o365ps only now.

  2. Michelle Graham

    I upgraded to Exchange 2016 on-premise, I noticed our default email policy “lowest” isn’t applied. It says changes have been made and they need to be applied. When I set up new users it is setting them up in the correct format. I want to add a new policy for out new domain but Im worried since the default lowest inst applied will the policy added when applied will it start acting as the default?

  3. J C

    what a lameo post.

  4. Pete Fenak

    Anyone aware if there has been any update to this. Have AD connect to Exchange online but no on prem exchange. Would ideally like to be able to a apply a policy or similar to add a new email domain for users without preparing a csv to edit ad attributes for all users and or building an exchange server

  5. Zoltan Erszenyi

    Paul, in a pure cloud-only tenant (no hybrid, no DirSync), the primary email address doesn’t stick in one particular environment.

    Are you aware of any setting/process in O365 which controls it and I, as the tenant admin, have authority to configure it?


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