You may find that the default address policy does not
apply automatically even though you have checked “Automatically Apply Email
address policy” and “Allow Inheritable permissions” checked. Take a look at your email address policies. Make
sure the default policy has the highest priority. Check to see If you have any
policies that were created pre-Exchange 2007 that were not converted and have not
been applied in Exchange 2007. If these polices were applied to an object in Exchange
2000/2003 and not upgraded to 2007 then those objects will not get the new
default address applied.
Delete the invalid policy and the force applying the
policy with this one liner:
Get-mailbox -ResultSize Unlimited | set-mailbox -ApplyMandatoryProperties
