Block all emails sent to users other than mail users in Postfix

Hello, I am Munou.

Currently, I still receive spam emails. This is because I only send and receive emails with taro@eyes4you.org.

The thing is, FreeBSD users like 'pop' and 'root' exist, and it seems that spammers are abusing the forwarding function to send emails to those users first, then forward them to other users, eventually reaching taro.

Therefore,
I will edit /usr/local/etc/postfix/sender_access
to configure more strict delivery settings.

vim /usr/local/etc/postfix/sender_access

info1@* REJECT
/^To:/    REJECT
/^To:.*taro@eyes4you.org/    OK
/^Cc:.*taro@eyes4you.org/    OK
/^Bcc:.*taro@eyes4you.org/   OK

The red text is what I added this time. In other words, I will only accept emails sent directly to taro@eyes4you.org in the To field.

I don't know if this will solve the problem, but as a countermeasure for now...