Thanks for the extra info, Geir. I vaguely remember the Pluto server, believe it or not! In fact, I've just tracked down an email from 2001 and have had a quick look at the headers. Sure enough, Pluto is the receiving server.
Thanks for the planets cartoon, Robert - very amusing.
The other problem with naming servers after planets is you are a little stuck when a planet ceases to be classified as such. A 'Pluto' server, for example, would need to be downgraded to a dwarf server!
- Henry