===== Header and Body checks ======
Header and Body check are very simple to use with postfix:
<file>
header_checks = regexp:/etc/postfix/header_checks
body_checks = regexp:/etc/postfix/body_checks
</file>

Obsah souboru header_checks:
<file>
/^Subject: .*Varovani pred novou verzi podvodnych e-mailu/ REJECT
</file>