It isn't possible to exclude admins from the reporting details if they receive the email messages. If the admins need to receive copies of the email messages, but you don't want them to be included in reporting, then you can make use of the Reviewer List in the Email Campaign. To configure the Reviewer List, follow the steps below:
  1. Email > select Email Campaigns
  2. Select the Campaigns tab
  3. Find your Campaign and click Manage
  4. Now follow these steps to Send The Message To Reviewers