PO approval notification is not going

Hi ,

We create a Requisition and got the autocreated PO. There is an approval hierarchy. But the approver didn’t get the notification email.

Can you please help us to get the PO approval notification for the PO. Status of mail is still 'mail' it should be ' sent'

we have checked-

# Notification Mailers -  up

# Control Queue Cleanup is down

# We havent changed any parameters and configuration

Please help me,

Thanks

Piyush