The new tools, announced Thursday, come as e-mail service providers such as MSN and rivals Yahoo and America Online race to diminish users' spam fury, which has heightened in the face of a seemingly endless tide of unsolicited commercial e-mail messages.

Demonstrating the extent of the problem, Microsoft said Thursday that it blocks roughly 2.4 billion spam messages a day, or nearly 80 percent of e-mail messages that reach MSN servers, via layers of filtering and with the help of several spam-fighting tools.

A new tool that was introduced as part of an upgrade to the Hotmail service this week is a technology that prevents images in e-mail from loading unless the e-mail sender is listed in the receiver's contact list. Aside from clogging up users' networks, Microsoft said that many of the images in spam messages contain "Web beacons" which send a message back to the sender when the message is opened, allowing spammers to distinguish active e-mail accounts.

Users can still choose to scan the text and manually open the images if they wish.

Another recent antispam addition to the service is what Microsoft calls a Human Interactive Proof technology, which requires customers to interpret and manually retype a random sequence of letters and numbers in an attempt to keep spammers from setting up computer generated accounts using bots, scripts, and other automated methods.

The Redmond, Washington, company said that since the technology was introduced last December, it has seen a 20 percent decrease in online attempts to set up new e-mail accounts.

Microsoft made spam elimination a focus of its new MSN 8 service, which launched late last year. At the same time, AOL put spam at the top of its hit list while introducing AOL 8.

Microsoft and AOL aren't the only ones concentrating on canning spam, as other industry players have also moved to take spammers to court and lobby for tough penalties against sending spam.

In fact, EarthLink won a $16 million suit against a spammer Wednesday.

Additionally, major e-mail providers have recently banded together to discuss initiatives that would further reduce the flow of spam.