To delete a dialog on a computer, hover over the dialog in the list and click the following button:
To delete a dialog on a mobile device, move the dialog to the left and click on the "Delete" button:
The dialogue will be deleted only by you. Therefore, when new messages appear in the dialog, it can recover. The conversations can be deleted completely if the following conditions are met:
Each of the interlocutors will delete the dialogue.
The time interval between removal of dialogue by each of the participants is the time when new messages will not be received in dialogue.