Block or Reject any postmaster or other users by postfix MailScanner

vi /etc/MailScanner/MailScanner.conf
# Send Notices = no
# Notices From = MailScanner
# Notices To = postmaster
# Local Postmaster = postmaster

Deliver Unparsable TNEF = no  to yes

Block By Postfix main.conf

/etc/postfix/sender_access:

# /etc/postfix/sender_access
#
# Black/Whitelist for senders matching the 'MAIL FROM' field. Examples...
#
oneuser@example1.com      OK
junk@spam.com             REJECT
marketing@                REJECT
info@                     OK
example.marketing.com     REJECT
someexample.com           OK


postmap /etc/postfix/sender_access