Where are bounced messages

Your software
My Mautic version is: 5.2.3
My PHP version is: 8.2.26
My Database type and version is:

Your problem
My problem is: Bounced messages don’t appear in bounces segment

These errors are showing in the log:

Steps I have tried to fix the problem:

I’m using Amazon SES for sending emails.
I have set up the bounced connection according to Joey Keller’s tutorial.
I have a list with 1100 leads. I can’t imagine, that all still have a valid email address.
Unfortunately, I don’t receive any information about not delivered emails.
Where do these emails from the Postmaster, telling me that an address is not valid and thus did not reach the recipient, go?

Kind regards

Christian