Never miss a new card entering a specific column by following these steps to setup column watching.
Open the column menu and click on the “Watch Column” option to start watching that column. If you decide later to no longer receive notifications about the activity of a column, simply open that column menu and select “Stop Watching Column”.
With the watch column enabled, you will see the watcher icon on that column. This alert will also generate a notification in the Alert panel. If you have email notifications enabled, you will also receive an email notification about this card.