An email filter is an app that impedes undesirable emails from entering a given mailbox. An immense percentage of the email communication around the world is composed of spam email messages: offers for pills or money, forged banking notifications, and so on. That is why, it is rather important to set up filters in order to avoid not only spam email messages, but also any possibility of being ripped off in some way. Spam filters detect different things, so as to ensure higher levels of protection – specific words or the frequency with which they occur in the text, the sender’s email address, or the IP of the sender’s mail server. Web hosts frequently use the services of 3rd-party spam-monitoring organizations that offer up-to-date databases to render email filtering easier and more effective without affecting legitimate email messages, even if they contain suspicious words.