Hello Varun,
- You have to write your mail trigger code in include ZXQQMAU20 (User-exit QQMA0014)
- When the Notification is Saved the mails will be triggering.
- Mail trigger function module can be SO_DOCUMENT_SEND_API1
- A Ztable vs needs to be created for MailId, Planner Group (assuming that mailIs will be triggering on the basis of PlGrps)
Show this to your ABAPer, he will be doing that. I do not consider this to be a difficult one.
Good luck
KJogeswaraRao