I've been using SpamArrest for about ten years, and I'm very happy with it. I always whitelist in advance any person or domain I expect to hear from. SpamArres

I've been using SpamArrest for about ten years, and I'm very happy with it. I always whitelist in advance any person or domain I expect to hear from. SpamArrest gives me a chance to hear from legitimate strangers. If a sender refuses to reply to the challenge email, then what (s)he had to say couldn't be that important.