# StableEmail Inbox Send (Own Address)

> StableEmail Inbox Send (Own Address) is a paid API for AI agents from stableemail.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Sends an email from the user's own StableEmail inbox/forwarding address rather than the shared relay address

## Facts

- Endpoint: POST https://stableemail.dev/api/inbox/send
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/stableemail-e28b216d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__nfVuae6WfPrNlPWT85z4

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability stableemail-e28b216d -d '<json body>'
```

Example prompt: Send an email from my StableEmail inbox address to john@example.com with the subject 'Invoice Ready' and body 'Hi John, your invoice for April is attached. Thanks!'

## When to prefer this

Choose this endpoint over the shared relay send (relay@stableemail.dev) when the recipient should see the email coming from the user's own inbox address rather than a generic StableEmail relay. Ideal for cases where sender identity and trust matter — e.g. transactional emails, personal outreach, or branded subdomain communication. Costs the same $0.005 per send as the relay option but preserves the sender's own address identity.

## Known failure modes

- Inbox not verified or DNS/SES setup incomplete — returns verification error
- Insufficient USDC balance to cover $0.005 per-send fee — returns payment failure
- Invalid recipient email address format — returns validation error
- Inbox expired or not topped up — returns inbox status error
- Rate limit exceeded — returns throttling error
- Missing required fields (to, subject, body) — returns bad request error

## How this service works

Send from your inbox address ($0.005)

## Output

Returns a delivery confirmation with a message ID and send status indicating whether the email was successfully dispatched from the user's own StableEmail inbox address.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "cc": {
   "type": "array",
   "items": {
    "type": "string",
    "format": "email",
    "pattern": "^(?!\\.)(?!.*\\.\\.)([A-Za-z0-9_'+\\-\\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$"
   },
   "maxItems": 50,
   "minItems": 1
  },
  "to": {
   "type": "array",
   "items": {
    "type": "string",
    "format": "email",
    "pattern": "^(?!\\.)(?!.*\\.\\.)([A-Za-z0-9_'+\\-\\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$"
   },
   "maxItems": 50,
   "minItems": 1
  },
  "html": {
   "type": "string",
   "maxLength": 256000
  },
  "text": {
   "type": "string",
   "maxLength": 256000
  },
  "replyTo": {
   "type": "string",
   "format": "email",
   "pattern": "^(?!\\.)(?!.*\\.\\.)([A-Za-z0-9_'+\\-\\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$"
  },
  "subject": {
   "type": "string",
   "maxLength": 998,
   "minLength": 1
  },
  "username": {
   "type": "string",
   "allOf": [
    {
     "pattern": "^[a-z0-9][a-z0-9-]{1,28}[a-z0-9]$"
    },
    {
     "pattern": "^(?!.*--)"
    }
   ]
  },
  "attachments": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "content",
     "contentType",
     "filename"
    ],
    "properties": {
     "content": {
      "type": "string",
      "maxLength": 5000000
     },
     "filename": {
      "type": "string",
      "maxLength": 255,
      "minLength": 1
     },
     "contentType": {
      "type": "string",
      "maxLength": 255,
      "minLength": 1
     }
    },
    "additionalProperties": false
   },
   "maxItems": 5
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/stableemail-e28b216d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from stableemail.dev](https://www.zero.xyz/host/stableemail.dev/llms.txt)