Users Not appearing the GAL after being imported through the use of a script

This applies to specifically after a Exchange 2003 to 2007 migration where the mailbox manager rules were not deleted prior to Exchange 2003 being decomissioned.

This is one that has had me stumped for a while.
The issue is as follows
After adding users in bulk to AD from a script or any other way than through ADUC and then mail-enabling them in EMC they do not appear in the GAL or All Users.
The problem is that the msExchHideFromAddressLists is set to FALSE. If this attribute is set to the user will appear in the GAL.
This is however not the issue.
The problem lies with the Default Address policy.

The solution is as follows
Create a new address policy in the EMC and make sure that is has the following settings

Applies to all recipients
The Addresses are
@externaldomainname.com.au
@internaldomain.local

In ADSI Edit navigate to
CN=Recipient Policies,CN=Org,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=domain,DC=Local
Right click on the name of the policy that you just created
Change the attribute
msExchPolicyOrder to 2147483647

Restart all Exchange services

Open the EMS and type the following

Get-user –resultsize unlimited set-mailbox –applymanadoryproperties

Open OWA and verify that all users are now in the GAL