[MalcolmDiggs]

I wouldn't say that it's "bad", but, personally, I don't think it'd be in my best interest to use a pay-wall.

Most of the emails I get are from people who want my money (vendors/businesses). But I get the occasional email from someone who wants to give me their money (a potential client). I wouldn't want to do anything that would stop a potential client from sending me an email.

Two other concerns:

1. The practicality aspect. If I'm requiring bitcoin, then the sender needs to be bitcoin-literate, which not everybody is. If I'm requiring a credit card, then the charge is too small to justify the merchant charges.

2. The branding aspect. Do I really want to be known as someone who charges for emails? I'm not sure that message would align with very many people's personal brand/image. I'd be more likely to wait on the sidelines until charging-for-emails is commonplace, then I'd feel comfortable joining in. But until that time comes, you might have a first-mover-disadvantage. This creates a problematic catch-22 for any SaaS/PaaS offering this kind of thing. (Few people wanting to be an early-adopter).