Go to the home view in the imp app. There you should see all your call notifications. To the top left of the screen is a button that says 'Edit.'
Tapping 'Edit' gives you the option of selecting multiple notifications and editing them en masse. Simply tap the notifications that you would like to apply the same effect on and then tap the selection at the bottom of the screen that you wish to apply.
Making your selection and then tapping "Assign to List" at the bottom opens the option for you to move all selections to either the Greenlist, Greylist, or Redlist.
Marking a notification as unread will make that notification display as unread for all users on a multi-user imp box. This can be helpful if the landline gets a message that is intended for a certain person.
Lastly, you can DELETE multiple notifications quickly and easily but selecting everything that needs to go, and then tapping delete.
If you're done editing or need to start over, simply tap 'Done' to go back to the main home screen.