When part of a group in Outlook 365, by default you must scroll all the way down to the lower left of the navigation pane to see group mail. If you want to receive group mail in your inbox, double click the group and in the center of the screen you will see an ellipsis [...], click it and then choose settings. Finally, on the right-hand side of the screen choose the first option which is to Follow in Inbox.
If you do not see the DLS ALL group, simply choose Discover Groups and type DLS and you will see the the DLS ALL group with the option to JOIN. Once joined, repeat steps above to receive group mail in Inbox.
(see below pics)