Postfix getting spam to system users

[pernel]

I have a postfix + dovecot mail server with only one normal user. However i found that the postfix server receives spam mail to system users and creates mailboxes in "/var/spool/mail" for example for system users adm, apache, clamav, mysql, postgres and mail. I have a feeling that this makes my system more vulnerable. I tested this by sending email from my gmail to adm@myserver.se and it lands in the corresponding mailbox.
I tried to understand how to setup postfix so that it will recieve only mail to the one and only one "normal" user and reject or block mail to any of the system users from remote hosts.
Would appreciate any help.
Per

[doktor5000]

Hi there, you should probably check the postfix documentation for that as that is not really a Mageia-specific question.

See e.g. https://unix.stackexchange.com/question ... nding-mail or https://dan.langille.org/2019/01/25/usi ... recipient/ or https://www.cyberciti.biz/faq/howto-bla ... l-address/
and maybe https://www.postfix.org/RESTRICTION_CLASS_README.html