In 2002, his open relay, along with 24 others, was used by a computer worm to propagate.

Well, that's called an open relay, which is what spammers have traditionally used.

By 2003 less than 1% of corporate mail servers were available as open relays, down from 91% in 1997.

Running an open relay became even a bigger problem than before.

Many people contend that open relays make it too easy to send spam.

And open relays don't usually keep a log of who routes through them either.

All ran open relays, usually fast and often with hazardous baton passes.

And a server operating like this is known now as an "open relay."

So it's generally not the case that public servers are open relays.

Since most servers were configured as open relays, this was a common practice.