# is-email-hosted-by-fastmail-bulk

> is-email-hosted-by-fastmail-bulk is a paid API for AI agents from email.intel.rallylive.ca, paid per call via x402, $0.1/call, status unknown (last checked 2026-10-19).

Checks whether up to 20 domains' email is hosted by Fastmail in a single concurrent batch call, returning one result per domain with per-item error fields and a failure count.

## Facts

- Endpoint: GET https://email.intel.rallylive.ca/bulk/email/hosted-by/fastmail?utm_source=zero.xyz
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-19
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/is-email-hosted-by-fastmail-bulk-17a1287b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_x_5IoHwv92hePkp2wZg8f

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-fastmail-bulk-17a1287b
```

Example prompt: Can you check all 15 domains in my prospect list and tell me which ones are hosting their email with Fastmail? Here are the domains: acme.com, bravo.io, charlie.net, ... (up to 20).

## When to prefer this

Use this endpoint when you have a list of 2–20 domains and need to check Fastmail hosting status for all of them efficiently in one call rather than making separate single-domain requests. It is preferable to the single endpoint whenever you're doing bulk enrichment, processing lead lists, or building data pipelines that require concurrent lookups with ordered, per-item results.

## Known failure modes

- Individual domain DNS lookup failures captured in per-item error field without failing the whole batch
- Exceeding the 20-domain limit may result in rejection or partial processing
- Malformed domain inputs may trigger per-item errors
- Network timeout on DNS resolution for specific domains
- Service unavailability returning a top-level error for the entire batch

## How this service works

Bulk is email hosted by fastmail: up to 20 domains in one call, processed concurrently, results in input order with a per-item error field and a failure count. Same answer per item as the single endpoint. Batch enrichment for agents that hold a list. $0.10 per batch.

## Output

An ordered array of results matching the input domain list, each containing a boolean indicating whether that domain's email is hosted by Fastmail, a per-item error field if the lookup failed, and a summary failure count for the entire batch.

## 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-fastmail-bulk-17a1287b/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)