Most of the emails sent around the world nowadays are spam, i.e. undesired messages with various offers or with links to malicious software. Not only are such email messages annoying, but they also present a threat to your own personal computer, not to mention that you may be swindled. This is the reason why plenty of mail service providers make use of email filters, which are applications that ‘scan’ all incoming email messages and filter out the unwanted ones based on their content – what words or phrases an email consists of and how often they are referred to, what web site a given hyperlink leads to, what outgoing mail server the email comes from, and so on. Some web hosting companies also make use of the databases of spam-tracing organizations dedicated to providing the most up-to-the-minute info about unsolicited messages, to make certain that their customers will not receive any email message in their mailbox that should not be there.