# StableEmail Update Subdomain Settings

> StableEmail Update Subdomain Settings is a free API for AI agents from StableEmail at stableemail.dev, callable via MPP, Free, status unknown (last checked 2026-10-09).

Update catch-all forwarding settings for a custom email subdomain on StableEmail

## Facts

- Endpoint: POST https://stableemail.dev/api/subdomain/update?utm_source=zero.xyz
- Price: Free
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-09
- Activations on Zero: 0
- Provider: StableEmail
- Docs: https://stableemail.dev
- Website: https://stableemail.dev
- Tags: email, send, inbox, forwarding, subdomain, social
- Canonical page: https://www.zero.xyz/c/stableemail-update-978fd766
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_6Ju7c1tqSINzGdezC3zT7

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-update-978fd766 -d '<json body>'
```

Example prompt: Update my StableEmail subdomain 'mycompany' so that all catch-all emails are forwarded to inbox@gmail.com.

## When to prefer this

Use this endpoint when you need to update the catch-all email forwarding destination for an existing StableEmail custom subdomain, such as routing all inbound emails to a new address or disabling catch-all forwarding entirely.

## Known failure modes

- Invalid subdomain format — must be 3-30 lowercase alphanumeric or hyphen characters, no double hyphens
- Invalid catch-all forwarding email format — must be a valid email address
- Subdomain not found or not owned by the caller
- Setting catchAllForwardTo to null clears forwarding with no error but may silently disable routing

## How this service works

Update subdomain settings (catch-all forwarding)

## Output

Confirmation that the subdomain's catch-all forwarding settings have been updated, reflecting the new forwarding email address or cleared forwarding configuration.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "subdomain"
 ],
 "properties": {
  "subdomain": {
   "type": "string",
   "allOf": [
    {
     "pattern": "^[a-z0-9][a-z0-9-]{1,28}[a-z0-9]$"
    },
    {
     "pattern": "^(?!.*--)"
    }
   ]
  },
  "catchAllForwardTo": {
   "anyOf": [
    {
     "type": "string",
     "format": "email",
     "pattern": "^(?!\\.)(?!.*\\.\\.)([A-Za-z0-9_'+\\-\\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$"
    },
    {
     "type": "null"
    }
   ]
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/stableemail-update-978fd766/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)