One of the things that annoys (some) sysadmins is users exchanging filesover the email system, often for good technical reasons, and over theyears a lot of people have devoted a lot of effort to trying to persuadeusers to switch to various other mechanisms.

It's not going to happen. (Well, you knew that already if you've been paying attention .)

People keep exchanging files over email because email remains the mostvisibly secure and convenient way of doing so, especially to naiveusers.

Especially in light of the difficulties that they present in returningmultiple bits of information , you might sensibly askwhy DNS blocklists opt to return information as IP addresses, instead ofsomething more flexible. A related question is why DNSBLs are queriedin such an odd way, by reversing the octets of the host address you'reinterested in.

The IP address thing is simple: everyone has has gethostbyname() orits equivalent in their standard library. Especially if you just wanta yes or no answer (and that'

Virtualization is in the air around here, partly as a way of beingenvironmentally friendly; fewer physical machines means less power andheating and so on. Now, I'd like to be environmentally friendly, but oneof the issues with virtualization is that getting into it for anythingimportant has significant startup costs.

One of the reasons we run different services on different machines tostart with is for fault isolation, so we don't have all of our eggsin one basket. Virtualization reverses that; if you lose