Spam Blocker blocks unwanted advertising messages on the mail server. It is a simple and convenient tool for preliminary analysis, blocking and deleting incoming advertising messages (spam) on the mail server. Spam Blocker helps to get rid of annoying email advertising by analyzing correspondence before it is loaded from server. It checks all mail and receives the headings of all messages from the user's mailbox (email addresses, addressee names, message subject, etc.) and analyzes the messages for spam content. In addition to the already existing rules and blocking lists of unwanted advertising messages, all the criteria of sorting messages are defined by the user, which allows setting the program according to individual needs. It works with several mailboxes and allows users to configure spam filter settings for each account according to their purposes and needs.