Thanks for the reply. I have configured the SES as mentioned in the link. But regarding the reply by email address, which one should I use? domain or subdomain.
I have added replies+%{reply_key}@mail.example.com as the reply by email address since my verified domain is mail.example.com. I have tested by sending an email to a non-existent Gmail from my discourse. It’s been two days, nothing on the bounced list.