Hello. I run a business doing price comparison of goods in different online shops. Result of comparison subscribed users recieving by email. Users subscribing by themselves on my site. I got into situation when one of the users claims I am doing spam. I have replied to email from SpamCop, but it was unsuccessful and were ignored. User have an easy option to unsubscribe of his email by simply following a link in the email, but instead he wrote a complain. How to resolve the issue? Can you please tell me how can I defend myself against such fake complaints, and how should I act in this situation? Thank you.