Junk e-mails offering links to porn sites, miracle weight cures, Viagra and the chance to win a million dollars, have plagued surfers for years.

Hotmail, as one of the most popular web-based e-mail services with around 1.3 billion messages every day, is one of the worst affected

In a deal with anti-spam firm Brightmail, Microsoft hopes to significantly decrease the number of unsolicited mails reaching subscribers' accounts.

Decoy emails

"Unsolicited junk e-mail is a global problem in the industry today that affects not just Hotmail users, but e-mail users everywhere" said General Manager of MSN Hotmail Rick Holzli.

Hotmail facts

1.3 billion messages sent daily Half of spam blocked at Hotmail's gateway 110 million users 10% of Hotmail receive mail from pre-approved list

"This deal shows MSN's continued commitment to aggressively fight spam and provide our users with a world-class e-mail experience," he said.

Under the deal, Brightmail will filter spam before it is delivered to the Hotmail users' inbox.

It has a list of more than 200 million decoy e-mail addresses, set up just to attract spam. As soon as a piece of junk e-mail is received the source can be added to a list of banned addresses.

Keeping the spammers at bay is a costly business for Hotmail, which is now encouraging users to transfer to paid-for services or set up a list of pre-approved addresses.

Spammers jump from address to address to avoid being stopped and have so far managed to find ways around all the anti-spam filters put in their way.

Easy target

EuroISPA (European Internet Service Providers' Association) has been a prominent lobbyer on the issue of spam. According to member Joe McNamee, Hotmail is a victim of its own success.

"Hotmail is an incredibly easy target," he said.

"It is easy for spammers to invent a random string of letter and put Hotmail at the end of it. The chances are a load of them will be valid addresses," he said.

He believes that Hotmail should take every opportunity to block spam.

"For example, MSN gives consumers to block individual spam sources. If substantial numbers of their customers are blocking particular e-mail or IP addresses, this gives a clear indication of where spam is coming from, and therefore incoming mail can be safely treated as spam," he said

The European Union has passed legislation that will make spam illegal from next October.

EU ban

Users receiving spam will be able to contact their Information Commissioner (formerly the Data Protection Commissioner) to have the source investigated.

If that source is found to come from within the European Union then legal action can be taken.

Currently the definition of spam varies wildly from country to country. In Italy customers plagued by spam from an Italian source are able to claim compensation, while the UK Information Commission has a more lenient attitude to what constitutes spam.

"Work needs to be done to make sure the ban has teeth and will actually work. Guidelines need to be drawn up to make it as easy as possible for users to get action," said Mr McNamee.