When someone else moves, edits, recolors, or changes the images on cards you created, Magpie waits until ten minutes pass with no new change on that board, then sends one email for the board. It lists each change in the order it happened, such as a card moving to In progress and then to Done. Several edits in a row to the same card appear as one line, and reordering cards within a column is not included. If changes keep arriving, the email is sent an hour after the first one.
The email ends with how many of your cards are in each column of the board. Turn these emails off with Kanban card updates on Account settings.