drop email or domains in postfix

1 – create an alias

echo 'devnull: /dev/null' >> /etc/aliases

2 – force postfix to reload changes in /etc/aliases

newaliases

3 – create a regex rule to postfix forward emails to /dev/null

cat >> /etc/postfix/virtual.regexp <<EOF

# delete emails from *sales@gmail.com
/^.*sales@gmail.com/ devnull

4 – test the given email against the rules one file

postmap -q 'john-sales@gmail.com' regexp:/etc/postfix/virtual.regexp

5 – update .db file after edit it (isn’t necessary postfix restart)

postmap /etc/postfix/virtual.regexp