In case of emails doesn't get delivered, it could be due to generation/injection/delivery related issues.

1) To determine whether the emails are being generated or not, you must first obtain the generation log before requesting the delivery logs. If the generation log is missing, inform SRE Team. If the generation log was located, look for the IP address of the server from which it was fetched the delivery log.

2) Failed Injection logs - CAT can verify the same or consult infra team

3) Failed delivery logs - If that server did not return the log, inform the DE with the right generation log

Note - The correct generation log is ECMPLOG. Please do not distribute the NO Queue log

4) Halon - If you didn't find the log there, it didn't arrive at Halon. This should be checked basis on #1 or #2

If you find the successful delivery log on halon dashboard no need to consult DE team
In halon check delivery log after 30 minutes , it will take time to reflect the log