To Reject a Task

Follow these steps to reject a work task that has been assigned to you.

From the Inbox, open the task that has been assigned to you.
From the Tasks menu, select Reject.

The Reject Task page appears. For example,
In the Notify section, select each person that you want to be notified about the rejection of the work task.
If you want to notify the workflow owner, ensure that Notify Workflow Owner is selected.
You can enter a Reason For Rejection in the box.
When you are finished, click Reject.

The work task is rejected.