It has been said before, but now new research has confirmed it: Never open email that you think is probably ‘spam’ (an unwanted and unsolicited mass mailing). Eight out of 10 spam emails contain covert tracking codes that enable the sender to record and log recipients’ email addresses as soon as a message is opened, according to new research carried out by Masons, the law firm. Spam volumes can double within weeks of opening such messages, it concludes.

Most spam is illegal or contractually prohibited, says Shelagh Gaskill, a Masons partner. There may, for example, be a breach of the Data Protection Act, depending on how the email addresses were obtained; and there may be a breach of the contract that the sender has with its Internet service provider.

But so far, it seems, legislation is not proving a deterrent: “The people sending it could not care less about the law,” says Gaskill. Moreover, the Email Preference Service, a list to which people can add their email addresses to say they do not want to receive email marketing, is ineffective, she says. A new European directive on protection of email privacy, due to come into effect in the UK later this year, may improve matters. In the meantime, businesses are advised to apply a spam filter and disable the preview pane function on applications such as Microsoft Outlook or Express.