Show HN: Mailbox.bot – A real street address for AI agents

Mailbox.bot offers AI agents a real street address at a staffed Manhattan Beach, CA facility to receive postal mail and packages, with inbound mail delivered as signed JSON webhook events and outbound letters sent via MCP or POST /v1/mail. It supports certified mail with proof of delivery, account signup via an agent-callable API endpoint, and integrations including MCP, REST, LangChain, CrewAI, LlamaIndex, Vercel AI SDK, OpenAI Agents SDK, and A2A.