How does an email Spam filter work?
For most email users, using an email Spam filter to get rid of Spam is the only viable alternative to manually sifting through large numbers of junk email every day. There are different kinds of filters: User defined filters are included in most email clients today. With these filters you can forward email to different mailboxes depending on headers or contents. For example, you would put email from each of your friends into a mailbox named after them. You can also use these same filters to forward email to the trash if the origin or contents are suspicious. To do this you need to carefully look at any Spam emails you receive. Try to notice common characteristics, recurring patterns in senders email addresses, dubious claims in the subject line and so on. You will soon find that Spam filtering using a small number of rules can eliminate a large number of Spam emails. Header filters are more sophisticated. They look at the email headers to see if they are forged. Email headers contain i
