I have two questions:
1. What is it that Linkedin does to keep resurfacing to my inbox?
2. How come Linkedin is not penalized for the atrociously enormous quantities of spam it sends? (either by mail processors or by the authorities). I have lost count of how many times I have turned notifications off.
There are a pile of preferences under: https://www.linkedin.com/mypreferences/d/categories/notifica...
If those are turned on, then you have not opted out, so it isn't spam.
(And yes, feel free to rant about opt-in by default, and just how many places you need to turn things off. I'm not saying LinkedIn is reasonable about this... just saying that under the status quo, you need to take some initiative to control it.)
Real spammers don't give you an option to opt out, some even include fake "unsubscribe" option, which in reality, only confirms to them that the e-mail is active and valid.