I would NOT remove the negative feedback.
Did he still have items listed on eBay when he was supposedly on vacation for 3 weeks
IMO, negative feedback should also be left if this was the case!!
Definitely a good point.
In any case, it sounds like he deserves the negative. If he persists in emailing you, report him to EBAY.
Hey, do you have a link to his feedback? I am curious as to what type of feedback he is getting now.