Spam mails: E-mail advertisements, publications or other materials sent to users who have not taken the initiative to ask for, emails without clear communication methods, senders, return addresses, etc.; use China Telecom's network to violate the security policies or terms of service of other ISPs Actions and other emails that are expected to cause complaints.
According to the above definition, which of the following are not spam mails?
 An email with winning information from an unknown website.