My reply is: the software has no known bugs, therefore it has not been updated.

Coming back to the topic of computer security, the TCP Wrapper is an example of such a safety net. I wrote it when my systems were under attack by someone who appeared to walk through walls.

For many people my software is something that you install and forget. I like to keep it that way.

Qmail out of the box works fine, so people will want to use it regardless of licensing restrictions, even when the software does not ship with their system software.

The challenge with Postfix, or with any piece of software, is to update software without introducing problems.

The Postfix security model is based on keeping software simple and stupid.

At the time the Sendmail program had a very poor reputation with respect to security, with four root vulnerabilities per year for two successive years.