Postfix: mail to invalid addresses being forwarded to postmaster instead of bouncing
 

Mail going to invalid email addresses are being forwarded to postmaster@domain instead of being bounced. How can I fix this?

postconf -d | grep mail_version gives the following:
mail_version = 2.2.5

Thanks in advance!

This normally happens when the email cannot be returned to the sender.
Is the return address routeable?

Thanks a lot for the reply!

The return address exists and is routeable.

Is there perhaps a setting in main.cf to fix this? Or maybe an aliasing issue?

Currently in the /etc/aliases file, mailer-daemon, mail, postman, post_office, abuse and spam are being forwarded to postmaster.

Thanks!

No ideas? I'm getting pretty desperate at this point.

mailer-daemon is being aliased to postmaster. Could this be causing it? Is it dangerous to remove this alias?