There's some things right on the edge, like Netflix as an example. They're never trying to sell me anything; they've got my $N/month. The emails (that I don't read until now to sample them) are suggestions of shows I might like. User retention mail and promoting the shows they own the rights to are spam, but not all of it is.

My credit union sends infrequent warnings about recent phishing and scam techniques. I never opted in to those emails but they're not useless for everyone and possibly do net good.

I think a good heuristic is to look at the value provided in emails; if the recipient stands to benefit significantly more than the sender (on average) then it's not spam. Sure, my credit union has to deal with less hassle reversing charges or resetting passwords but it's quite a lot more hassle to be a victim of phishing or other scams.

Every few months, or when there's a big disaster, I get spam from Unicef, trying to get me to donate more money.

The emails are undoubtably spam, but (in my opinion) Unicef itself isn't an evil organisation.