* Spam is not email from legitimate companies with valid contact details that have an opt out that you forgot to click when you signed up with them. That's legitimate marketing emails. You might argue they also shouldn't exist, but they are a different category.*
No, they’re all spam. It’s just that some spam is significantly worse than others.
Edit:
this just reminded me of an interaction with a customer when I worked at a dialup ISP over 20 years ago. We would routinely get abuse reports about spam coming from our network that would turn out to be a family computer with a virus. We would disable their account until we got ahold of them, and then help them run antivirus or redirect them to a local shop to fix it.
But this one time my boss is like “Hey you wanna pretend you're the email manager? We have an actual spammer sending ads for a local business through our smtp servers”. We were all laughing at the audacity of it, they were sending thousands of the same message out, I think it was for a tackle shop.
When I called the guy to let him know why we disabled his account he immediately got angry at me, I vividly remember him saying “It’s not spam, it’s for a business!!” I explained to him that it doesn’t matter, it’s just as bad, and could get the whole company blacklisted from sending emails. Turns out his friend owned the business, and convinced him to install something that sent emails through outlook express.
The reason I got that duty is because I had no problem being confrontational back then. I remember telling him that I think he should be fined, and permanently banned from the internet. But that we’ll only let him back on if he uninstalls the thing.
He called back indignantly asking why we were allowing some other spam. I had to explain that it was from another network, and we’re trying to stop it, and that if every ISP were like us then it would barely be a problem.
I wonder if that business spams through google now.