How can I create a mailing report with drupal views?
You can create list of mailing using views but you can't filter the results based on groups it was sent. To achieve this you will need to implement the handler or alter the query to filter result via hook.
Alternate method is to create a Mailing Summary civireport giving access to the specific report from the 'access' tab of the report.
You can create your own drupal permission via hook or custom permission extension and than selecting the permission from the access tab.