This link, given by an earlier poster, now seems to be working as I have used it to report an incident of unwanted spam email sent to me recently and originating in the UK. As you probably know this type of activity is illegal, and this organisation polices companies who break the rules.
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Just to be clear, these are the rules, quoted directly from this site;
From 11 December 2003, the Privacy and Electronic Communications (EC Directive) Regulations 2003 became law and two new rules came into force regarding email marketing.
1st Rule ? when they send marketing emails to you, the sender must not conceal their identity; and ? they must give you a valid address for opt-out requests This rule actually applies to all marketing messages sent by electronic mail (see ?electronic mail? below), regardless of who the recipient is. 2nd Rule ? Senders cannot send such messages unless they have your prior consent to do so.If you have been the victim of unwanted emails, from any UK source I suggest you file a complaint.
Regards Kevin