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.

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.

All men are by nature equal, made all of the same earth by one Workman; and however we deceive ourselves, as dear unto God is the poor peasant as the mighty prince.

But, in the name of the experimental method and out of our poor knowledge, are we really entitled to claim that everything happens by chance, to the exclusion of all other possibilities?

A rich man is nothing but a poor man with money.

False shame accompanies a man that is poor, shame that either harms a man greatly or profits him; shame is with poverty, but confidence with wealth.

A person cannot love a plant after he has pruned it, then he has either done a poor job or is devoid of emotion.

Poor is the man whose pleasures depend on the permission of another.

Men who are scandalized at the lack of freedom in Russia do not ask themselves how real is liberty among the poor, the weak, and the ignorant in capitalist society.

Hope is a flatterer, but the most upright of all parasites; for she frequents the poor man's hut, as well as the palace of his superior.

There's a constant flow of child actors. It's kind of funny to watch the new crew come through. I think, You poor little things. You're going to have to struggle for a long time.

Content makes poor men rich; discontent makes rich men poor.

You need massive recruitment to tell the poorest of the poor what is possible.

Life is not a matter of holding good cards, but of playing a poor hand well.

I think it's time to do clean-up for a generation. I believe this is one of the movies that hits home for all colors and all races. Everybody I talk to, black or white, suburban, rich or poor, can relate to rejection, can relate to not having a father or a mother.

Money is a poor man's credit card.

Success in life comes not from holding a good hand, but in playing a poor hand well.

No one is rich whose expenditures exceed his means, and no one is poor whose incomings exceed his outgoings.

I think Morse's thing about being a poor policeman but a good detective is a very good description of him.

When I got outta High School I was driving a truck. I was just a poor boy from Memphis, Memphis.

They've got us surrounded again, the poor bastards.

Nowadays there is more dynamism in chess, modern players like to take the initiative. Usually they are poor defenders though.

It is only the poor who pay cash, and that not from virtue, but because they are refused credit.

If you're poor and you do something stupid, you're nuts. If you're rich and do something stupid, you're eccentric.

Substantive and procedural law benefits and protects landlords over tenants, creditors over debtors, lenders over borrowers, and the poor are seldom among the favored parties.