How have I never known about this? I've spent so much time manually pruning large email inboxes...
Where is that button?
It's on mobile app.
Can't seem to find it. But I wonder if you have to have Categories enabled ...
You are right. For me, I always see a blue-colored "Unsubscribe" link on the right-end of the From header in mails that are in Promotions or Social categories.
I've just spent 5 minutes exploring the Gmail Android app and the web interface on windows and I can't find this in either. I also searched Google for "Gmail manage subscriptions" and don't see it mentioned anywhere. Just links to manage Google payment subscriptions.