Rules-Based

• A Rules-based spam filter allows the user to determine which email is junk mail and sorts accordingly.
  
  

Content Based

• Content-based filters block certain words or phrases of incoming mail.
  
  

White List and Black List

• White Lists and Black Lists filter your email either by names in your address book as approved senders, or by blocking known spammers based on a blacklist.
  
  

Challenge/Response

• Challenge/Response filters monitor mail by requiring unknown senders to respond with a security code before allowing their email.
  
  

Community-Based

• Community Based anti-spam filters are based on a community of users that report known spammers. Some of the popular email programs use this type of filter. According to Consumersearch.com, this may be a sufficient enough spam filter.
  
  

Forms of Spam Filters

• Spam filters come in software programs, like all-in-one suites to purchase and download. There are also web-based filters available that filter spam automatically that can be purchased from a website or provided by your Internet Service Provider. Consumersearch.com warns the free spam blockers may not filter as well as the purchased programs, and you may still receive spam in your inbox.