I think it was nostr:npub1az9xj85cmxv8e9j9y80lvqp97crsqdu2fpu3srwthd99qfu9qsgstam8y8 who said once that people like email because it's stable and they know their messages are there waiting for them when they need them.
That's probably why email clients end up being the de facto RSS reader of many people with newsletter subscriptions, hence this idea for trying to get that to work in a Nostr context: nostr:nevent1qqsqqqx3n9ls2cu8qf5gxfhuzvt3kssv8v7etw20enna2t5yqkqj5xqppemhxue69uhkummn9ekx7mp0qy2hwumn8ghj7mn0wd68ytn00p68ytnyv4mz7qg3waehxw309ahx7um5wgh8w6twv5hschkr36
But now I'm thinking newsletters just fit the NIP-23 RSS style subscriptions better and mixing them up with email is a bad idea.