These days, many companies distribute marketing newsletters via online platforms. In terms of capabilities, such platforms are quite diverse: they send out advertising and informational messages, harvest statistics (for example, about clicked links in emails), and the like. At the same time, such services attract both spammers, who use them to send their own mailings, and cybercriminals, who try to gain access to user accounts, usually through phishing. As a result, attackers also get their hands on user-created mailing lists, which allows them to disseminate mass advertising or phishing messages that filtering systems sometimes let through.
