Vault Service Account in DAG

Hello,

I need a solution. We've got a mixed mode Exchange environment with 2007 and 2010 DAG. We can put the 2010 DAG Service to the target list, but when we like to archive no mailbox is shown.

Is it neccessary to put the Vault Service Account also to the DAG or could it stay on the 2007 Service till the end of the migration

The Archiving System in Enterprise Vault 10.0.3

Thanks in advance