So you're saying you voluntarily gave out your primary email address and then don't like that they are emailing you? Why give it out in the first place then? It's free to setup a dummy email address for these purposes.

Unless you're complaining about getting reminder emails from upcoming doctor appointments, bills and the like. But my impression was that getting those are a feature...

I could set up multiple accounts. But then I have to check multiple accounts. Either way, I have to go out of my way to make email as pleasant to use as instant messaging already is.

This is definitely a case of "that's just how you use it", as my phone number is relatively accessible and many services have asked for it, so I get plenty of spam straight to my phone via almost every messaging means that can be tied directly to my phone. That means things like whatsapp in addition to plain old SMS.

That’s because email providers have it backwards.

They could deny by default unless the sender is in a contact list.

But I mean the messenger list has to be updated to allow people in every time you meet someone worthy?

You are still doing list management.