I left linkedin a long time ago but I still get emails when someone wants to connect. I must have opted out of those a dozen times! Nope, still get 'em.
Also, pedant speaking here, "in one click" isn't really an accurate description of this process.
I hope Google shared this sort of information with LinkedIn. "Your daily emails are reliably considered spam, by people who actually want to use your services."
i wish they did have a feedback loop. i have a catch-all domain and an employee that was terminated with us left so now I get the barrage of emails to a general box for his LI account.
well he never updated his linkedin to a new email and you have to sign in to unsubscribe. well, i don't want to reset his password because i can see he still uses the LI and there is no way to stop these emails. seems like making it impossible to unsubscribe would violate CAN-SPAM.
DKIM is not a feedback loop. A feedback loop is when someone hits spam on one of your emails, the provider lets you know what message caused the user to hit spam. If you have a unique message id or something else in the email encoded in you can tell who it was and not send them any more emails.
Actually since Gmail now has three tabs and the linkedin emails end up in the 'social' folder, it is less of a bother. Once in a while you go in and mass delete.
Also, pedant speaking here, "in one click" isn't really an accurate description of this process.