The proof-of-work signup is a clever bypass for the verification problem. Worth flagging the other side of the coin though. Agents that need to operate inside existing human inboxes, not parallel accounts, are a different design surface entirely. We built empla.io around that premise. 13 AI employees that work through the founder's own Gmail, no new addresses, no separate login. The interesting tension is deliverability: Gmail and Outlook still penalize agent-origin mail heavily, which is why we piggyback on the user's sender reputation. Curious how Zoidmail plans to handle that the moment people try to actually send outbound from these accounts at any real volume.