[MM3-users] How to let mailman log every single email that it sends out?

I'm curious about the configuration required to have Mailman record logs for every individual email it sends. I see that it sends to the entire list, but I'm interested in obtaining log entries for each email sent to every individual subscriber on the list. How can I access this information?

Is it a postfix setting, or a Mailman3 setting? I have checked /var/log/mail.log and all the logs under /var/log/Mailman3/* Mailman is running on Ubuntu 18.3

Thank you! Mohsen