Most of the emails sent around the world these days are spam, i.e. unwelcome messages with different offers or with hyperlinks to malicious software. Not only are such emails annoying, but they also pose a risk to your own personal computer, not to mention that you may get tricked. That is the reason why a lot of email service providers make use of email filters, which are software applications that ‘scan’ all incoming emails and filter out the undesired ones on the basis of their content – what words an email message includes and how often they are referred to, what site a given hyperlink points to, what mail server the email message is sent from, etc. Certain providers also rely on the databases of spam-monitoring organizations dedicated to the provision of the most up-to-the-minute info about undesired messages, to make certain that their clients won’t get any email message in their mailbox that is not supposed to be there.