# Is Email Hosted By Posteo – Change Watch

> Is Email Hosted By Posteo – Change Watch is a paid API for AI agents from email.intel.rallylive.ca, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-24).

Monitors whether a domain's email is hosted by Posteo and alerts when the result changes, returning a diff with before/after values and timestamps.

## Facts

- Endpoint: GET https://email.intel.rallylive.ca/watch/email/hosted-by/posteo?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-24
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/is-email-hosted-by-posteo-change-watch-b5e551f5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ASx9F3ZBVJG6vzs7A8Orz

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 is-email-hosted-by-posteo-change-watch-b5e551f5
```

Example prompt: Keep an eye on whether posteo.de is still hosted on Posteo email and let me know as soon as that changes — I want to see what flipped and when it happened.

## When to prefer this

Choose this endpoint when you need to be alerted to changes in Posteo email hosting status for a domain over time, rather than just a one-off check. It is ideal for scheduled polling workflows where you want diff-aware results (what changed, before/after values) without maintaining your own state. If you only need a single point-in-time answer, prefer the non-watch variant. For bulk monitoring of many domains simultaneously, prefer the bulk sibling endpoint.

## Known failure modes

- Domain not previously queried — no baseline for comparison, 'changed' may be null or false on first call
- DNS lookup failure via Cloudflare DoH returns an error or inconclusive result
- Domain does not exist or has no MX records — returns false with no comparison data
- Stored previous result expired after 90 days — treated as a fresh first check
- Payment of $0.02 USDC not fulfilled — request rejected with 402 Payment Required

## How this service works

Change watch for is email hosted by posteo: runs the check, compares it with the result from your previous call for the same domain (kept 90 days) and returns the current answer, changed true/false, the fields that changed with before/after values, and when it was last seen. Schedule it to be alerted when this changes. $0.02 per check.

## Output

Returns the current Posteo-hosted boolean result, a 'changed' true/false flag comparing against the prior call result (retained for 90 days), a list of changed fields with before and after values, and a timestamp of when the status was last seen.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/is-email-hosted-by-posteo-change-watch-b5e551f5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from email.intel.rallylive.ca](https://www.zero.xyz/host/email.intel.rallylive.ca/llms.txt)