Tag Archives: milter

Limit Number of Recipients in To and Cc with Postfix for Authenticated Users

By | July 5, 2014

The simplest way to restrict the number of recipients in To or Cc with Postfix is the use of HEADER_CHECKS. You put in your Postfix main.cf a line like this: header_checks = pcre:/usr/local/etc/postfix/header_checks And you create a file /usr/local/etc/postfix/header_checks which contains this: /^To:([^@]*@){10,}/ REJECT Sorry, your message has too many recipients. /^Cc:([^@]*@){10,}/ REJECT Sorry, your message has too… Read More »