One thing I've learned while doing email marketing is how easy it is to get banned by email service providers. They have extremely low tolerance for spam, the standard is that if more than 0.1% of the email you send is marked as spam, you get sacked, banned, gone. Thus, your marketing of whois emails as spam will HAVE A BIG EFFECT of them getting sacked from their ESP. Don't just ignore them, report them. And tell your friends to do it as well.