Mailbox enabling error when AD is configured for a resource forest. "Unable to resolve acc. in re (4260309)

Whenenabling a mailbox with AD configured for a Resource Forest, it fails to resolve the linked master account and fails to verify that it exists in a forest that is different from the forest that hosts Microsoft Exchange.
The following error message is seen from the wlog file:

Unable to resolve acc. in resource forest. Used account like: services/binf\services\accountname

The process is taking a fully qualified domain name and account name and adding them together.

In the Notes Migrator Admin Driven Migrator,
1. Edit Default Settings |Active Directory Configuration
2. When dealing with the resource forests, do not specify AD usernames in the format of domain\userid
3. Specify userid likein the formatuser@domain.company.com or user