Inbound mails not delivering to oracle apps after user approved - workflow

Issue:Inbound mails not delivering to oracle apps after user approved in workflow and are failing with time out error

Solution:

I cleared the unwanted INBOX mails for wf@ account and bounced the workflow services , now I see all INBOX mails got processed.

Ref: 11i-12 A Guide For Troubleshooting Workflow Notification Emails - Inbound and Outbound (Doc ID 831982.1)