We'd recommend adding new acceptance statuses "Recommended for Acceptance" and "Recommended for Rejection" that can be set by Chairs only.
Please go to the page:
Overview => Settings => Manage Acceptance Status... and create new acceptance statuses "Recommended for Acceptance" and "Recommended for Rejection".
This can be done easily by copying the existing entries "Accepted" and "Rejected" and changing the "Short Title" and "Full Title".
Scroll down to the option "Assignment Rights" and use the checkboxes to do define who shall have access to each acceptance status.
Please set the new statuses accessible only to Chairs /Track Chairs and hide all existing statuses like "Accepted" and "Rejected" from them.
Now only Chairs / Track Chairs will have access to the "Recommended for..." statuses and can use them to flag all submissions before the final verdict is made by the program committee.
NB: ConfTool does NOT send an automatic mail to authors when the status is changed.
For further information please refer to:
Evaluating the Review Results and Setting the Acceptance Status of Submissions