Autogenerated email to user

Hi,

One user is getting autogenerated messages regarding the requistion releases.

He is getting the messages from production system to his mail box.

Please inform how to stop the emails to the user.

"Message is as below (with different release numbers):

Requisition release 50008847 00060 Created By Lynne Denty

.

Please Click the Below Link to log on and Approve or Reject the Work-

item.

-

---"

Regards,

Dhanu