A spam filter is a software app that runs on an email server and monitors all incoming emails in order to impede any unsolicited ones from reaching a particular mailbox. Several examples of such emails would be: offers for pills or money, fake bank statements or email attachments that contain malicious code sent with the idea of infecting your PC. Email filters usually ‘scan’ the content of an email and if they detect certain keywords or other dubious content, they either delete the email message or deliver it to the Junk/Spam folder instead of the Inbox folder. Some hosting companies combine their own spam filters with up-to-the-minute databases from spam-tracing organizations, so as to guarantee higher levels of security for their customers. Such databases contain patterns, email server IPs and other info about spam messages recently detected by these organizations.