Perhaps I am using a different level of security but here is what I do to quickly read digests.
1. I double-click on the digest title. This opens the list of the titles of individual messages.
2. I double-click the first message and quickly read it. If I wish to save this message, I print it, usually on used paper that has text on one side with a pencil slash thru it.
3. I press the escape key. (Gotta give my left hand something to do. My right gets to do all the mouse clicks. (grin) That message disappears and only its title shows.
4. I double click the next message, read, escape, repeat until all messages quickly are read.
5. After the last message escape, I do an extra escape which highlights the digest title.
6. Click delete on the toolbar. The entire digest of messages shoots off to the deleted items folder. About once a month I scantitles only in the deleted items folder. I seldom find anything more I want to save so I delete all messages 31-60 days old.