I am sick of seeing all the opt-in pages telling me to add what is often a noreply email address to my contact list, or almost as bad is adding a real address to my contact list for someone I don't really class as a contact.This is how I handle "whitelisting" (example for Gmail)It works for now, and if the spammers work around it, I will just make it a little more specific by using specific information within the headers, or part of the unsubscription notification.