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.

Postfix keeps running even if one Postfix process dies; Windows requires that someone restarts the service.

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

I was going to visit IBM for six months as a visiting scientist. Now, six months is a lot of time, so I came with a whole list of projects that I might want to work on.

Most of the effort in the software business goes into the maintenance of code that already exists.

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