[DanBC]

Or they confirm the email address is live and they get lots more?

Standard advice for years has been don't unsub from email you haven't subbed to.

[ThomPete]

For actual spammers yes. Linkedin isn't a spammer in that category.

[DanBC]

Linkedin is sending bulk email to people who have not opted in and who have not confirmed the opt in.

That's pretty much the definition of spam. It's unsolicited, it's bulk, it's email.

[ThomPete]

Yes but the question was whether you had opted out.

I haven't seen anyone claiming Linkedin keeps sending after that but I might be wrong.