I created a "rule" in Mail app (v15) to have all my substack subscriptions go to a Substack folder on my iCloud mail. It's my only rule. The Active checkbox is checked. I log out of the Mac at the end of the day. When I arrive to work the next day, I log in, and notice there are 10-15 substack messages (mixed in with a dozen other emails) sitting in iCloud Inbox. Why are they there? Should they not have been automatically routed to the Substack folder in the cloud throughout the night (or the moment I fired up Mail app, if nothing else)? I did some searching and a forum post told me I had to type option-command-L to make the rule "take". I tried that, but the substack messages did not budge. Then I went through and meticulously selected each substack message (quite a labour intensive process, though I suppose I could have used a search filter) and then pressed option-command-L. Voila!, the messages disappear from Inbox and appear in Substack folder. But, the thing is, at that point, with all the messages manually highlighted, I could just as easily have dragged them over into the Substack folder myself. Can someone explain to me what the point of the Mail rules are,... or what am I misunderstanding?