Undelivered mail notification to Sender's Outlook from SOST

I have come across a scenario where Sender receives a mail on his Outlook in case a mail is not delivered to recipient from SOST in PRD (SOST shows status as transmitted). I have been trying to replicate the same scenario in Quality environment but unable to receive notification to my Outlook in case mail is not delivered but status in SOST shows transmitted. Any idea if i need to maintain any setting or check anything.