he is the EU legislative document on spam
http://www.dti.gov.uk/industry_files/pdf/regulations_20030918.pdf
Here is the section about unsolicited mails
"Use of electronic mail for direct marketing purposes
22.(1) This regulation applies to the transmission of unsolicited communications by means of
electronic mail to individual subscribers.
(2) Except in the circumstances referred to in paragraph (3), a person shall neither transmit, nor
instigate the transmission of, unsolicited communications for the purposes of direct marketing by
means of electronic mail unless the recipient of the electronic mail has previously notified the
sender that he consents for the time being to such communications being sent by, or at the
instigation of, the sender.
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(3) A person may send or instigate the sending of electronic mail for the purposes of direct
marketing where
(a) that person has obtained the contact details of the recipient of that electronic mail in the
course of the sale or negotiations for the sale of a product or service to that recipient;
(b) the direct marketing is in respect of that persons similar products and services only; and
(c) the recipient has been given a simple means of refusing (free of charge except for the
costs of the transmission of the refusal) the use of his contact details for the purposes of
such direct marketing, at the time that the details were initially collected, and, where he
did not initially refuse the use of the details, at the time of each subsequent
communication.
(4) A subscriber shall not permit his line to be used in contravention of paragraph (2)."