Different naming policy for mailbox and Office 365 group

[tsvetelin]

Hello, 

I know that there are naming policy settings available for Office 365 groups applied onto the mailbox addresses. But is there a way to enforce a naming policy only on the group mailbox rather than everywhere?

We want to create a "NewProject" group and the mailbox automatically named "newproject.team@our.org".

The reason to ask is that we have mail aliases (before migration to Microsoft 365) that can be hijacked that way, i.e., if someone creates a group "ceo@our.org", the group mailbox will start receiving emails sent to the alias. So if there is an alternate solution than a suffixing mailbox, it will be great too.

Any help is appreciated.

[#2]

You can block certain "words" to prevent them from being used in the policy (https://docs.microsoft.com/en-us/microsoft-365/solutions/groups-naming-policy?view=o365-worldwide#cu...). The naming policy itself only applies to Microsoft 365 Groups, there is no way to have a policy that applies to user mailboxes in Exchange Online.
You can also limit the creation of Groups so that only admins, or designated people are allowed to do it.

[#3]

Thank you, @Vasil Michev! :)