In a previous life I wrote the software that controlled my physics experiments. That software had to deal with all kinds of possible failures in equipment. That is probably where I learned to rely on multiple safety nets inside and around my systems.

Defect-free software does not exist.

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.

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.

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.

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.

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.

When I write software, I know that it will fail, either due to my own mistake, or due to some other cause.

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

Sure, but competition is good for the user.

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

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

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

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.

This will surprise some of your readers, but my primary interest is not with computer security. I am primarily interested in writing software that works as intended.

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

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.

One bug in an SMTP server can open up the whole machine for intrusion.

Windows favors multi-threading, which means that a service is implemented by one single process.

Writing software that's safe even in the presence of bugs makes the challenge even more interesting.

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

Lack of documentation is becoming a problem for acceptance.

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

In a previous life I wrote the software that controlled my physics experiments. That software had to deal with all kinds of possible failures in equipment. That is probably where I learned to rely on multiple safety nets inside and around my systems.

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

Adding functionality is not just a matter of adding code.

Roosevelt's magic lay in one facet of his personality: He knew how to take the risk. No other man in public life I knew could so readily take the challenge of the new.

Focusing your life solely on making a buck shows a certain poverty of ambition. It asks too little of yourself. Because it's only when you hitch your wagon to something larger than yourself that you realize your true potential.

Art teaches nothing, except the significance of life.

If it came to saving the life of one priest or sacrificing the life of an entire congregation, the church would save the life of the priest. Which is backwards, of course.

Work is the meat of life, pleasure the dessert.

All literary men are Red Sox fans - to be a Yankee fan in a literate society is to endanger your life.

At the end, the realization is that she had to get to a place in her life where she could drop her guard and make peace with the fact that whether she had a small amount of time, that she had to kind of live it completely through, instead of living by the rules.

You have choices to make about what you do with the rest of your life.

From the standpoint of observation, then, we must regard it as a highly probable hypothesis that the beginnings of the mental life date from as far back as the beginnings of life at large.

I want to have babies one day but not right now. When I do it I want to do it really well. I want it to be my best project in life.

Any judge who allows an adulterer with a live-in girlfriend to terminate the life of his wife should be impeached.

I can assure you, public service is a stimulating, proud and lively enterprise. It is not just a way of life, it is a way to live fully.

The work which is manipulated looks a little boring to me. I think life is pretty strange anyway. It is wooo, wooo, wooo!

With an eye made quiet by the power of harmony, and the deep power of joy, we see into the life of things.

This isn't life in the fast lane, it's life in the oncoming traffic.

The good parts of a book may be only something a writer is lucky enough to overhear or it may be the wreck of his whole damn life and one is as good as the other.

Sometimes life's so much cooler when you just don't know any better and all the painful lessons have not hammered your head open yet.

My life is so full of surprises, nothing surprises me any more.

I love children and I love men, but I can't commit to either for the rest of my life.

Pop music, disco music, and heavy metal music is about shutting out the tensions of life, putting it away.

Yes, I am Algerian of Moroccan origin through my parents, but all my life is Algeria. I was born there.

At one point in your life, you'll have the thing you want or the reasons why you don't.

I tell my students to try early in life to find an unattainable objective.