Opt out of marketing

Surely if you opted out of receiving marketing information etc it means that the organisation should not be sending you marketing information in any format and if the organisation does send you marketing information by law they can be fined?

I am wondering why I am receiving an email notifiying me of updates to threads I am following that contains marketing information for a Lexus motor car?  Surely that cannot be right if you have opted out from receiving marketing information from CC and third parties by ticking a box as Lexus would be the third party?