Postfix keeps running even if one Postfix process dies; Windows requires that someone restarts the service.
I want to avoid locking people into solutions that work only with Postfix. People should have a choice in what software they want to use with Postfix, be it anti-virus or otherwise.
Writing software that's safe even in the presence of bugs makes the challenge even more interesting.
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.
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.
When I write software, I know that it will fail, either due to my own mistake, or due to some other cause.
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.
The challenge with Postfix, or with any piece of software, is to update software without introducing problems.
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.
I don't expect an overnight change of all desktops to what the US Military used to call B3 level security. And even that would not stop users from shooting themselves into the foot.
As of today, the Postfix mail transport agent has almost 50,000 lines of code, comments not included.