Most of the spam e-mails I see are using gmail, I agree would be ideal to have an option to block only e-mail not I.P. address.
Some proxy/disposable e-mail services were created also specifically for the purpose to stop spammers, so people don’t need to give out their main personal e-mail but only a proxy address that can be destroyed if spammers start to attack that.
Protonmail has a feature sort of like this called “simplelogin,” which allows people to create new temporary addresses and sub-domains: