I used to get so upset about these emails that I sent replies similar to yours - some folk got upset that I thought they intended what they had sent me
and some were too scared not to forward it - that about says it all really
I now just delete them and if someone keeps sending then I do a similar reply but if they don't like it I just block them as a sender cos frankly life is way too short to have friends like that
I also don't like cute photos of puppies or chimps or sunsets, angels or wise quotes of the day
Sadly it seems most of the people I know think these are wonderful ways of keeping in touch without actually making any personal contact whatsoever - hence I have few real friends by my reckoning but better that than joining them in the rounds of rubbish forwarding