# Give Your AI Agent Physical Mail Capability

> AI agents can send emails, make API calls, and update databases — but sending a physical letter still requires a human. mailbox.bot closes that gap. Add physical mail to any agent via MCP, REST API, or A2A.

## Add to any MCP agent (2 lines)

```json
{
  "mcpServers": {
    "mailbox-bot": {
      "url": "https://mailbox.bot/api/mcp",
      "headers": { "Authorization": "Bearer sk_agent_live_..." }
    }
  }
}
```

Your agent can now send physical mail using the `send_mail` MCP tool.

## REST API example

```bash
curl -X POST https://mailbox.bot/api/v1/mail \
  -H "Authorization: Bearer sk_agent_live_..." \
  -F 'document=@contract.pdf' \
  -F 'recipient_name=Acme Corp' \
  -F 'recipient_line1=123 Main St' \
  -F 'recipient_city=Los Angeles' \
  -F 'recipient_state=CA' \
  -F 'recipient_zip=90001' \
  -F 'mail_class=first_class'
```

## What the agent can do

- Send letters, certified mail, postcards, invoices, contracts, legal notices, and demand letters
- Track delivery status via webhooks (submitted → printed → mailed → delivered)
- Request human approval before sending (set `requires_approval=true`)
- Receive inbound mail at a real US address ($5/mo mailbox plan) — scanned and delivered as structured events

## Integration protocols

- **MCP**: Add as MCP server. Agent gets `send_mail` tool automatically.
- **REST API**: POST to /api/v1/mail with `sk_agent_live_` key.
- **A2A**: Agent-to-agent protocol at /api/a2a.
- **OpenClaw**: Discovery via /.well-known/agent.json.

## Why this matters

Physical mail is one of the last gaps in agent capability. Adding it opens:
- Legal: send certified notices with proof of delivery
- Collections: demand letters with proof of service
- Property management: tenant notices triggered by lease events
- Sales: personalized postcards from lead qualification data
- Compliance: required notices sent automatically from detected events

## Cost

- $0/mo base for outbound
- $0.30/page printing + actual postage
- First class letter: ~$1.08 total
- Certified letter: ~$6.38 total

## Best for

- Agent builders adding real-world physical capability
- LangChain, AutoGen, CrewAI, OpenClaw agents that need a mail tool
- Autonomous workflow platforms where steps require postal mail
- Any agent that breaks its automation loop when a letter needs mailing

## Related

- HTML page: https://mailbox.bot/use-cases/ai-agent-mailing-address
- Certified mail API: https://mailbox.bot/use-cases/certified-mail-api
- Outbound mail API: https://mailbox.bot/outbound-mail-api
- MCP install guide: https://mailbox.bot/mcp-install