# Emailable MCP by usefulapi (remote · emailable.usefulapi.io)

Verify email addresses with Emailable one by one or in batches, and read credits and batch results.

- Trust score: 64/100 (medium)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-10-17

## Components

- remote · `emailable.usefulapi.io`: 64/100 (this document), [markdown](https://verifymcp.io/servers/io-usefulapi-emailable/emailable.md), [page](https://verifymcp.io/servers/io-usefulapi-emailable/emailable)

## Channel facts

- Endpoint: `https://emailable.usefulapi.io/mcp`
- Transports: `streamable-http`
- Auth: `required`
- Version: `1.0.0`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-10-17.

- **Endpoint Security**: 78/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - Authorisation is enforced on tool calls, advertised via RFC 9728 protected-resource metadata. Discovery is public, which costs nothing: no tool can be invoked without a token.
  - HTTPS enforcement could not be verified: the plaintext port redirected somewhere other than https, so enforcement is unproven.
  - HSTS check failed: the Strict-Transport-Security header is absent.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
  - The authorisation server offers only Dynamic Client Registration (RFC 7591), which MCP 2026-07-28 deprecated in favour of Client ID Metadata Documents.
- **Transport & Reachability**: 0/100
  - Transport check failed: declared streamable-http, but the endpoint redirected instead of responding directly.
- **Schema Quality & AI Usability**: 78/100
  - 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 988 tokens (~247/item across 4 items; 4 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 17/100
  - Stability observed for 5 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 4 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 5 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 60/100
  - Spec-recency check failed: implements MCP spec 2025-06-18; the latest is 2026-07-28.

## Install

### How do I install the Emailable MCP by usefulapi server?

Emailable MCP by usefulapi is a hosted endpoint at https://emailable.usefulapi.io/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add --transport http io-usefulapi-emailable 'https://emailable.usefulapi.io/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "io-usefulapi-emailable": {
      "url": "https://emailable.usefulapi.io/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "io-usefulapi-emailable": {
      "type": "http",
      "url": "https://emailable.usefulapi.io/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.io-usefulapi-emailable]
url = "https://emailable.usefulapi.io/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "io-usefulapi-emailable": {
      "type": "remote",
      "url": "https://emailable.usefulapi.io/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add io-usefulapi-emailable --url 'https://emailable.usefulapi.io/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  io-usefulapi-emailable:
    url: "https://emailable.usefulapi.io/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "io-usefulapi-emailable": {
      "Transport": "http",
      "Url": "https://emailable.usefulapi.io/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add io-usefulapi-emailable -t streamable-http -u 'https://emailable.usefulapi.io/mcp'
```

### Other

```json
{
  "mcpServers": {
    "io-usefulapi-emailable": {
      "type": "http",
      "url": "https://emailable.usefulapi.io/mcp"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-10-17 (score 64, +1)

No change was recorded against any check on this day. Stability & Change Management went from 13 to 17. That category is still filling its 30-day observation window: 4 days of observed history at the previous scan, 5 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-14 (score 63, +3)

- [security] The server rewrote its instructions, which are the text every model session reads
- [functional] The server now declares the “prompts” capability
- [functional] First check of Schema quality: 100
- [functional] New prompt “getting_started”
- [functional] Server version: 1.0.0 → 1.1.0

### 2026-10-13 (score 60, 0)

- [functional improvement] Stability: unverified → 0.03

### 2026-10-12 (score 60)

First indexed and scored.

## MCP tools (4)

### `emailable_get_account` (~40 tokens)

Get account and credits

The Emailable account behind this API key: the owner's email and available_credits. Check it before a large batch. GET /v1/account.

### `emailable_verify_email` (~247 tokens)

Verify one email address

SPENDS CREDITS: verifies one email address and uses 1 Emailable credit (a test_ API key spends none). Returns state (deliverable, undeliverable, risky, unknown), reason, score (0-100), and flags: disposable, free, role, accept_all, no_reply, mailbox_full, plus did_you_mean (a typo fix), the detected user/domain/tag, mx_record and smtp_provider. A credit is returned for an unknown result. The call is never retried automatically. If the reply is {status: "try_again"}, the check took longer than the timeout: call again with the same email; repeats within 5 minutes are not charged. Emailable's terms allow verification of opt-in subscribers' addresses. GET /v1/verify.

Input parameters:

- `accept_all` (boolean): Run the accept-all check (default false). It slows the reply.
- `email` (string, required): The email address to verify.
- `smtp` (boolean): Run the SMTP step (default true). false is faster but much less accurate.
- `timeout` (integer): Seconds to wait for the result, 2-10 (default 5).

### `emailable_create_batch` (~235 tokens)

Create a batch verification

SPENDS CREDITS: starts a bulk verification of up to 5000 email addresses. Emailable takes 1 credit per email when the batch is created, and if the account has too few credits it may charge the account's saved card to buy more. A test_ API key spends nothing. The batch cannot be cancelled here, and the call is never retried: if it fails or times out, check emailable_get_account before trying again, because a retry can charge twice. Returns the batch id; poll it with emailable_get_batch. Emailable's terms allow verification of opt-in subscribers' addresses. POST /v1/batch.

Input parameters:

- `confirm` (boolean, required): Must be true. It confirms the user agreed to spend 1 credit per email (and a possible card charge for missing credits).
- `emails` (array, required): The email addresses to verify, 1-5000.
- `response_fields` (array): Only these fields in each result (default: all).
- `retries` (boolean): Retry mail-server answers for accuracy (default true). false is faster but gives more unknown results.

### `emailable_get_batch` (~258 tokens)

Get a batch verification

Status and results of a batch made with emailable_create_batch: message, progress (processed/total), reason_counts and total_counts (deliverable, undeliverable, risky, unknown). Batches of up to 1,000 emails also return the results inline in `emails` (30 days). They come in pages: up to `limit` results, fewer if the reply would get too long; ask for the next page with emails_page.next_offset. A bigger batch returns download_file, a temporary link (5 days) to a ZIP of a CSV: share it only with the account owner. Free to call. GET /v1/batch.

Input parameters:

- `id` (string, required): The batch id.
- `include_emails` (boolean): Include per-email results (default true). false returns the counts only.
- `limit` (integer): Most results per call, 1-1000 (default 100). A reply can hold fewer; use emails_page.next_offset for the next page.
- `offset` (integer): First result to return (default 0).
- `partial` (boolean): Include the results so far while the batch is still running (only for batches of up to 1,000 emails).

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/io-usefulapi-emailable/emailable#diagnostics

## Score history

- 2026-10-17: 64
- 2026-10-16: 63
- 2026-10-15: 63
- 2026-10-14: 63
- 2026-10-13: 60
- 2026-10-12: 60

## Common questions

### What is the Emailable MCP by usefulapi server?

Emailable MCP by usefulapi is listed in the public MCP registry as io.usefulapi/emailable. Verify email addresses with Emailable one by one or in batches, and read credits and batch results. This page covers its hosted endpoint (https://emailable.usefulapi.io/mcp).

### Is the Emailable MCP by usefulapi server safe to use?

Emailable MCP by usefulapi scores 64 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the Emailable MCP by usefulapi server expose?

Emailable MCP by usefulapi exposes 4 tools: emailable_get_account, emailable_verify_email, emailable_create_batch, emailable_get_batch. Their descriptions and schemas cost roughly 780 tokens of context every time the server is loaded.

### Does the Emailable MCP by usefulapi server require authentication?

Yes. Emailable MCP by usefulapi asked us for credentials when we connected, so you will need to authorise it in your MCP client before it can do anything.

### Is the Emailable MCP by usefulapi server still maintained?

Emailable MCP by usefulapi is still listed as active in the MCP registry. We last reached this channel on 17 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

## Links

- Remote endpoint: https://emailable.usefulapi.io/mcp
- Repository: https://github.com/m190/usefulapi-mcp
- Website: https://usefulapi.io/emailable/
- Changelog RSS feed: https://verifymcp.io/servers/io-usefulapi-emailable/emailable.xml
- Changelog JSON feed: https://verifymcp.io/servers/io-usefulapi-emailable/emailable.json
- HTML version of this page: https://verifymcp.io/servers/io-usefulapi-emailable/emailable