Delete the message and go on. There's one thing that's worse. When nobody contacts you at all.
Sweet jeez how low of an EQ you would need to possess to be annoyed by this kind of things?
Just delete and move on.
Are you gonna ask for a viagra seller blocklist next?
Recruiter spam is for now not nearly as bad as this - but with enough automation, it could be too. So "just delete it" is not a solution that scales. Maybe spam filters would catch it too, but then you'd risk missing authentic offers...
Subtract the LinkedIn spam and there is nothing there. There's nothing to be jealous of.
This. People complain about getting micro-harassed by recruiters when others are desperate for a job and would actually enjoy being head-hunted.