Triggering multiple mails for external Mail id when PO is created
I configured PO workflow and i used a standard program to send the mail to the external Mail id's of the users.
The thing is when a PO is created the user whos has to release the PO is getting a Mail in Business Workplace through work flow and simoultaneously a mail will go to his external mail with a message that So and so PO is created please release it.
As he cant keep on monitor his SAP Business workplace,whenever he get a mail to his external id,he will login to SAP and approves or rejects the PO.
Here the probelm is the external mail is keep on triggering for every 15 min as we scheduled the Job for ever 15 min.
So for the same PO number it is giving multiple mails to the external id until it is released.
It should be like one mail should trigger for one PO number instead of multiple mails for the sam PO number.
I'am unable to find the solution.
Please guide me with a solution.