Sent notification email to SC requestor of rejection and PO creation

Dear All

Please be so kind to let me know how to trigger a custom email notification to the requestor

for SC rejection and Po creation

I came across a couple of options as below :

1. Set alert configuration  it does not work as there is no option to customize text in here

General Configuration on Approval Alerts and Notifications - Supplier Relationship Management - SCN Wiki

2. I could set a check in DOC_check_BADI if any cart is rejected .. not sure on how I could trigger an email from there ..and specially how to check if PO gets created or not .

3. I could use the ZSRMOFFLINEAPPROVAL get report .. not sure on the code

4.  /SAPSRM/OFFLINEAPPROVALGET  again stuck at the code level .

Can some one please share some insight on which one is the most useful and if there is something in terms of code which can be shared for these 2 requirments

Please be so kind to help

Regards

Vinita