By Chris Morris BBC Europe Correspondent

Member states must decide how to punish companies and individuals

The new rules require companies to gain consent before sending e-mails and introduce a ban on the use of spam throughout the EU.

The unwanted junk e-mails, which are collectively known as spam, now make up more than half of all e-mail traffic.

The European Commission says they cost European business nearly $3bn in lost productivity last year alone.

So what do you do about it? - You ban spam.

But of course it is not that simple. Most of the spam which hits Europe comes from abroad, particularly from the United States.

International action

Concerted international action is needed. But there are signs that everyone is waking up to the scale of the problem.

Last week a court in California issued a huge fine against one spamming company, and the United States Senate has approved a bill banning spam in the US.

It hopes the House of Representatives will soon follow suit.

None of this will be a quick fix, but it is certainly a start.

The new EU rules also limit the ability of companies to use files known as "cookies", to gain information about people who visit their websites.