This is simply a waste of resources. Your message may have enough of its own context that none of the original message is necessary. Another point regarding replying to email is to do it promptly especially for those of us who are operating a small or home-based business. Since messages can be sent back and forth nearly instantly there seems little excuse to wait several days before responding to a message that requires a reply. There have been many cases of large corporations that either never reply to email queries or do so only with an irrelevant automated response.
Privacy is a big issue on the Internet and applies in many ways directly to email.
This is the junk mail of the Internet. Two important rules apply here. Do not send spam and do not reply to spam. Do not send spam because it is intrusive and a waste of time and money. Do not reply to spam because it simply validates your email address to the spammers and opens you up to receiving even more junk.