| I recently got an email from someone who had been receiving emails from my site asking him to confirm his subscription to my newsletter and his membership. He hadn't asked for either. Luckily, because I run a double opt-in system, he wasn't subscribed to my newsletter automatically. But still the 5 or 6 emails he had received were annoying enough for him to contact me. It turns out that someone was deliberately harassing him, and signing him up for every newsletter imaginable - at a rate of 40 a week! I thought it would be worthwhile spending a few minutes trying to help, so I modified my SendEmail function in utils/Email.asp. Now whenever it sends an email it first checks that the address isn't in my list of "blocked" email addresses. If it is, then information about the perpetrator is instead emailed to me. I can then forward it onto the relevant authorities who can surprisingly find out a lot about you given just the IP address and the time. In this particular case some very high-up authorities are taking a close look! Part 2: The IsEmailBlocked( ) function... | 
