Earlier quoted context omitted.
There's an entire cottage industry of linkedin scrapers that put a lot of effort into guessing your email address to enable cold outreach. I'm ashamed to say I worked at one such place for several months. Apollo is probably the most comprehensive source for this. It's creepy as fuck.
I’m a bit on the fence with this one. Sure, spam is bad, but they also enable you to reach out to somebody outside of the LinkedIn’s walled garden (personally, without automation). If it enables a tiny startup trying to solve the exact problem I have to reach out to me – I’d say it’s a net positive (but not by a huge margin), and having to blacklist @mongodb.com with their certifications bullshit is a price I’m ready…
Maybe the thought occurs that one is only accessible on LinkedIn on purpose and just because a recruiter from 8 years ago has your number, it's not up for grabs?