How can one atone for wrongdoing that occurred through backbiting or suspicion, without the ability to meet the individuals and apologize to them?

A Muslim must offer sincere repentance for backbiting and having ill thoughts about people, for repentance erases what came before it. Part of perfect repentance is seeking forgiveness from those whose rights were violated, if possible, and if it does not lead to a greater harm. If seeking forgiveness would lead to increased discord, then it is sufficient to seek general forgiveness without specifying the sin. If the person whose rights were violated cannot be reached, then it is sufficient to pray for them and speak well of them in the places where the backbiting occurred.