Notification to supplier for touchless POs

We are on 12.1.3 and use touchless POs(POs are automtically created and approved when planned orders released from ASCP or reqs created from WIP).The PO has the supplier contact on it with a valid email id  but no notification goes to the supplier contact.How can we enable notification being sent out to supplier contacts automatically for these touchless POs?

Thanks

Rahul