Can you please advise me how to set the PD eGroup settings so that I receive the list once a day in a digest format?

The eGroup no longer supports a digest mode.  The digest mode allowed you to get posts bundled together once a day, instead singly when they’re sent.  However, use of this mode was very problematic because it exposed normally hidden artifacts associated with emails sent using an HTML format.  That generally made picking out the true content of the message very frustrating.  This is a common problem with eGroups and is not something within PD’s control.