Can I delete these SystemMailbox from Exchange? They say legacy and have multiple warnings
I am trying to wrap up a migration from Exchange 2010 to 2016. I tried to remove an old BES throttling policy and it complains about still being associated with these mailboxes. I had noticed them before in the Exchange Admin Center but had ignored them up to now. What you can see in the Admin Center is they do not have any databases associated with them. I found the ID's in Active Directory under the Microsoft Exchange System Objects container and they show as disabled.
So my question is... can I delete these safely without destroying my Exchange environment!?