I've been monitoring the topic of blockchain-based email services for a little over a year. This could be a decent business opportunity given the limited options currently available.

What I'm wondering is how one establishes a reasonable cashflow business model around providing blockchain email services. I'm not talking about ICOs, which are fine to raise capital but are not, in and of themselves, a viable business model. Ad revenue is also not a good option, because the target customers attracted to using blockchain email will not be generally open to gmail-style data farming.

If I see any interest in this, I'll start a more meaningful discussion on it. My goal is determining whether to launch a venture in this domain.