Don't like the idea of charging for emails at all Blacksheep.
Regardless of the problems with spamming we don't want ot go down that road.
Must admit I did have a problem with spam but then I went and got my own email account with oneandone.co.uk and since then I've little or no spam. When I was using BT and Freeserve etc. for my email crikey I appeared a lot more popular.
Also I use a hotmail account for sites which require an email address but that I don't want anything from, works a treat and if you don't buy any extra space from hotmail they all fall off the bottom when it gets full.