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.

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

However, writing software without defects is not sufficient. In my experience, it is at least as difficult to write software that is safe - that is, software that behaves reasonably under adverse conditions.

As of today, the Postfix mail transport agent has almost 50,000 lines of code, comments not included.

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

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.

Like all software, Qmail can survive only when it keeps up with changing requirements.