Poison-pen letters are malicious messages sent to cause distress, harm, and damage to reputation. Synonyms for poison-pen letters include hate mail, vituperation, defamation, verbal abuse, character assassination, and smear campaign. These terms denote a deliberate attempt to discredit and destroy someone's image or standing, often through the spread of false or derogatory statements. The impact of poison-pen letters can be devastating, causing serious psychological trauma and creating enduring rifts in relationships. Therefore, vigilance and caution are necessary to prevent and counteract the spread of such toxic messages. Above all, kindness, compassion, and respect for others should be the guiding principles of our communication with others.