>> Surely they should both give exactly the same result? > > Maybe.. Depends a LOT on the options you pass to spamd when you start it.
Yes you're right - there's an error in the scripts on Bill Shupps shupp.org site which I used to make my box - it was calling spamd with -L for some reason. I expect someone turned it on for debugging and forgot to remove it again. Thanks! Nick...