+*--preview-url*::
+Specify the url for the link preview.
+The same url must also appear in the message body, otherwise the preview won't be
+displayed by the apps.
+
+*--preview-title*::
+Specify the title for the link preview (mandatory).
+
+*--preview-description*::
+Specify the description for the link preview (optional).
+
+*--preview-image*::
+Specify the image file for the link preview (optional).
+