I'm not quite sure. I understand your example about the change of address. I would suggest that it would represent one millionth of the problem, and I would certainly not like to see that being used as an opportunity to drive through the other million e-mails that would come my way.
Regarding the second example, again it may well be the case that I find an e-mail that I received but had not invited interesting. But that's still not the issue to me. It's accidental and something I haven't invited, and in the great, great majority of instances, it is not something I would find interesting and worthy.
Mr. Alexander-Cook drew a distinction several times between “unwanted” and “unsolicited”, and I don't quite know what the difference is. To me, if it is unsolicited it is unwanted.