Why can't you go for Oracle Alerts? You can get many materials in internet on how to create Oracle Alerts.
Can you try 'Delivery Opt'. Please check these documents for more details.
Mails are not Received Using Delivery Option while Submitting Concurrent Request In R12.1.3 (Doc ID 1339491.1)
Concurrent Request Upon Completion Or Complete With Warning Email Notification Is Not Sent Even If Notify Option Is Checked (Doc ID 1939040.1)
EBS 12.1 How to Integrate Business Events in Concurrent Processing? (Doc ID 1161254.1)
How To Use Business Events To Send Notifications When A Spawned Report Completes (Doc ID 1506980.1)
Hope this helps!
Is out bound sever properly define in notification mailer in your instance.
For this things to work from Oracle Application Manager setup make sure the WF mailer is up and running. If you are making changes in dev then make sure other notification are stopped or email address is null before testing.
As said by others, if you want to receive notification mails, yes, you need to define Inbound, Outbound Mail Box setups, notification mailer should up. These setups will generally do by Admin with the approval from client (as they need separate mail box).
If you are making WF Mailer up as suggested by Hari, you can also define 'Set override Address' (Workflow Administrator Resp. > Oracle Application Manager > Workflow Manager. Click on tick mark (or 'X' mark if not up) of Notification Mailers > Workflow Notification Mailer > Set Override Address). So that you don't need to stop the notifications. But in this case, you will receive all notification mails