A spam filter is a program that attempts to distinguish between legitimate e-mails and spam. These program often look for patterns that are common amongst spammers. Some of these patterns are simple, like using the word viagra a lot, or mentioning free often. Other patterns are more complicated, such as comparing the amount of screenspace used by images and text (a common trick between spammers is putting words like viagra in images, so the filters won't pick them up.). There's also patterns that look for tricks which spammers use to hide their true identity.

Trying one of these patterns on an e-mail is called a 'test'. Spam filters often work by assigning every test a score. Some tests return a positive score (like offering certainty on the identity of the sender), some a negative. In the end the score is tallied up. When the total score exceeds a threshold, the e-mail is considered spam. Depending on the settings the system adminstrator made, you will receive a bounce, the mail will be tagged spam, or plain deleted.

To make sure your e-mail does not trigger false alarms, you should test it against these spam filters. Our system will do this for you, and provide you with a detailed report.

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