Hi Priya
A message in delivering status for a long time might be indicative of a hanged thread. I'd suggest you check the audit log for the message to see if it had hanged indefinitely a the receiver channel.
Also, you can check the queue to see if the thread permanently assigned - refer to section Analysis and Troubleshooting of my blog below.
Handling and preventing messages stuck in To Be Delivered status
Rgds
Eng Swee