I have met Michael McClure and he is very friendly, open and non-snobby. I have heard of people reaching him by looking up his phone number, sending letters c/o any of his recent publishers, etc. However I don't think I should give out his email. Try any of these other ways. I think probably the best way to contact a writer is to exchange numbers at a poetry reading or other event -- that way the writer can see your face and get an idea who you are, which always helps.