It seems that the problem does not come from catchall or bounce. It looks like the email address you are using to send emails is not recognized by your outgoing server. Check that the sender is known. If this is not, change the OdooBot email (archived contact) to put an email known to the SMTP server

Same problem here, I wonder, where the address   mail.bounce.alias+441-res.users-19  ( or in my case bounce+141@...    or  bounce+139-project.task-82 @... ) are coming from.
 rs

just for example try to make it like this for your outgoing mail server:

these are the important things to set the outgoing mail server

1. SMTP Server = smtp.gmail.com
2. SMTP Port = 465
3. Connection Security = SSL/TLS
4. username = {your_email}
5. password = {your_password_email}