We are setting up Exchange 2013 as a multi-tenant and followed various documents and this works a treat with 1 exception - the default address policy is also applied.
We have address book policies for companya, companyb etc.. so the emails are bob@companya etc...
but the top level domain is: toplevel.co.uk
When it creates the account, it finds the correct address book policy and applies but it also applies the default one .. so the user is bob@companya AND firstname.lastname@example.org
We want to still have the default ones as we have users in toplevel.co.uk ... but tenants do not need this address