the microsoft ip reputation service

The Microsoft Ip Reputation Service

The United States is the number one generator of spam email, with Korea clocking in as the second largest contributor of unwanted email.
5% of all spam email, but identity theft (which is known as phishing) makes up 73% of this figure.
Standalone spam blockers are not as common as integrated blockers, but they prove just as efficient.
Standalone spam blocker software can easily be installed on to your computer, and allows you to preview your mail on the server before downloading it to your computer.
You have to open the spam blocker before checking your email software, though most filters let you automate this process.
Traceroute is often useful for tracing down the upstream providers of spammers who own their own net blocks.
An open Socks proxy is a security hole used by spammers to hide their originating IP address.
Spam can made to appear to come from the Socks proxy instead of the actual origin.
False positives (a non-spam e-mail message that is falsely tagged as a spam message by a spam filter) can be more worrisome than false negatives because they might represent important personal communications that the recipient might never see unless he carefully examines the messages trapped by his filter.
The use of spf by mail providers is purely voluntary.
Right now, unfortunately, spf isn't in widespread-enough use to be viable as a spam-detection tool though it is beneficial in preventing bounces to innocent mail users whose addresses have been forged into the spam.