# Mailcheer (remote · mailcheer.com)

Manage a Mailcheer email workspace: subscribers, segments, campaigns, transactional sends and stats.

- Trust score: 76/100 (medium)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-09-25

## Components

- remote · `mailcheer.com`: 76/100 (this document), [markdown](https://verifymcp.io/servers/com-mailcheer-mailcheer/api-mcp.md), [page](https://verifymcp.io/servers/com-mailcheer-mailcheer/api-mcp)

## Channel facts

- Endpoint: `https://mailcheer.com/api/mcp`
- Transports: `streamable-http`
- Auth: `required`
- Version: `1.0.1`

## 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 2026-09-25.

- **Endpoint Security**: 89/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - Authorisation is enforced on tool calls, but the challenge carries no valid RFC 9728 metadata, so a client cannot discover where to get a token.
  - HTTPS is enforced; there's no plaintext access path.
  - The HSTS (Strict-Transport-Security) header is present.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 79/100
  - 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).
  - AI-judged instruction clarity (good).
  - Context-footprint check failed: tool/resource definitions use about 1840 tokens (~131/item across 14 items; 13 tools + 1 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 10/100
  - Stability observed for 3 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 86/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 59% of tool parameters carry a description.
- **Tool Safety**: 94/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - 3 of 4 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation; "preview_campaign_send" implies "send" and declares readOnlyHint instead, contradicting what its own name says it does.
  - An AI judge read all 15 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 Mailcheer MCP server?

Mailcheer is a hosted endpoint at https://mailcheer.com/api/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 com-mailcheer-mailcheer 'https://mailcheer.com/api/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "com-mailcheer-mailcheer": {
      "url": "https://mailcheer.com/api/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "com-mailcheer-mailcheer": {
      "type": "http",
      "url": "https://mailcheer.com/api/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.com-mailcheer-mailcheer]
url = "https://mailcheer.com/api/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "com-mailcheer-mailcheer": {
      "type": "remote",
      "url": "https://mailcheer.com/api/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add com-mailcheer-mailcheer --url 'https://mailcheer.com/api/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  com-mailcheer-mailcheer:
    url: "https://mailcheer.com/api/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "com-mailcheer-mailcheer": {
      "Transport": "http",
      "Url": "https://mailcheer.com/api/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add com-mailcheer-mailcheer -t streamable-http -u 'https://mailcheer.com/api/mcp'
```

### Other

```json
{
  "mcpServers": {
    "com-mailcheer-mailcheer": {
      "type": "http",
      "url": "https://mailcheer.com/api/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.

### 2026-09-25 (score 76, −1)

- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server

### 2026-09-24 (score 77, +1)

- [security] Tool “get_campaign_stats” rewrote its description, which is the text the model reads
- [functional regression] Schema quality: pass → fail
- [functional] Schema quality: excellent → good

### 2026-09-23 (score 76, 0)

- [functional improvement] Stability: unverified → 0.03

### 2026-09-22 (score 76)

First indexed and scored.

## MCP tools (13)

### `send_email` (~288 tokens)

Send an email

Sends a single (transactional) email to one or more addresses. The sender must belong to a verified domain of the workspace — call get_account to see which ones. An address suppressed for a bounce, a complaint or by hand fails the entire call, with its reason. An unsubscribed address still gets an individual email (a reply, an invoice, an appointment); a newsletter or a prospecting email must carry `unsubscribe_url`, and is then refused to an unsubscribed address. Every address (to, cc, bcc) counts against the plan's monthly quota: past it, the call is refused (`quota_exceeded`) with the figures and the reset date — do not retry before that date. The email is sent immediately: this action cannot be undone.

Input parameters:

- `from` (string, required): Sending address on a verified domain. "Name <address@domain.com>" format accepted.
- `html` (string): HTML body.
- `replyTo` (string): Reply-to address.
- `subject` (string, required): Message subject.
- `text` (string): Plain-text body. At least one of html or text is required.
- `to` (required): Recipient, or list of recipients.
- `unsubscribe_url` (string): One-click unsubscribe https address. Required for a newsletter or a prospecting email: it makes the send refused to an unsubscribed address. Leave it out for an individual email.

### `get_account` (~72 tokens)

Workspace info

Returns the workspace this key grants access to, its scopes, plan, remaining emails this month (queued sends included), when the counter resets, billing status, member and domain limits, sending domains (verified or not) and registered senders. Call this FIRST: it tells you which address to send from before attempting anything.

### `list_subscribers` (~102 tokens)

List subscribers

Lists the workspace's subscribers, page by page. Use `cursor` with the `next_cursor` value from the response to get the next page. `status` filters on subscribed, pending, unsubscribed, bounced, or complained.

Input parameters:

- `cursor` (string): Next-page cursor.
- `limit` (number): 1 to 100, 50 by default.
- `q` (string): Search by address or name.
- `status` (string)

### `add_subscriber` (~179 tokens)

Add a subscriber

Adds or updates a subscriber. By default the person enters as PENDING and receives a confirmation email: that is double opt-in, and it protects the workspace's sending reputation. `double_opt_in: false` subscribes directly and must only be used when consent was already collected elsewhere — never on your own initiative. A suppressed or unsubscribed address is refused. An address gets at most one confirmation every 2 minutes and 3 per 24 hours: do not retry in a loop, read `confirmation_not_sent_reason` and `confirmation_retry_at` in the response.

Input parameters:

- `double_opt_in` (boolean): false = direct subscription without confirmation. Only request this on explicit instruction from the person.
- `email` (string, required)
- `firstName` (string)
- `lastName` (string)
- `tags` (array)

### `remove_subscriber` (~84 tokens)

Unsubscribe a subscriber

Unsubscribes an address and adds it to the workspace's suppression list: no more campaigns, automations, or sends carrying `unsubscribe_url`. The record is not deleted — that is what prevents the address from coming back on the next file import. This action cannot be reversed via the API: only the person can re-subscribe.

Input parameters:

- `email` (string, required)

### `list_suppression` (~136 tokens)

List suppression entries

Suppressed addresses, with their reason: bounced, complained or manually suppressed (nothing goes to them), or unsubscribed (no more campaigns, automations, or sends carrying `unsubscribe_url`, but an individual email still reaches them). The `scope` field tells whether the address is suppressed for this workspace only or for the entire platform. No tool removes an address from this list: that action is done manually in the Mailcheer workspace, because it is the one that can suspend a sending capability.

Input parameters:

- `cursor` (string)
- `email` (string): Look up a specific address.
- `limit` (number)

### `add_suppression` (~86 tokens)

Suppress an address

Adds an address to the workspace's suppression list. By default (`manual`), it will receive nothing further, neither campaigns nor individual emails; with `unsubscribe`, only campaigns, automations, and sends carrying `unsubscribe_url` are refused to it. Use when someone requests no further contact outside the unsubscribe link.

Input parameters:

- `email` (string, required)
- `reason` (string)

### `list_campaigns` (~53 tokens)

List campaigns

The workspace's campaigns, from newest to oldest, with their status: draft, scheduled, sending, or sent.

Input parameters:

- `cursor` (string)
- `limit` (number)
- `status` (string)

### `create_campaign` (~161 tokens)

Create a campaign draft

Creates a DRAFT. Nothing is sent: you then need to call send_campaign, or send it from the Mailcheer workspace. Content is written in plain text in `text` — a blank line separates paragraphs, "#" at the start of a line makes a heading. Always have the draft reviewed before sending.

Input parameters:

- `from` (string): Address of an already-registered sender. Defaults to the workspace sender.
- `kind` (string): newsletter, offer, announcement… newsletter by default.
- `name` (string, required): Internal name, visible only in the workspace.
- `preheader` (string): Preview text shown after the subject in the inbox.
- `subject` (string): Subject line seen by recipients.
- `text` (string): Plain-text content.

### `preview_campaign_send` (~170 tokens)

Preview a campaign send

Read-only: nothing is sent. Returns exactly what send_campaign would do right now — would it go out (and if not, why), and how many people would receive it. With `to`, reports address by address who is kept and who is excluded, with the reason (unsubscribed, bounced, complained, not in the list…). If the monthly quota is not enough, `would_send` is false, `blocked_code` is `quota_exceeded` and `blocked_details` gives the figures and the reset date. Call it BEFORE send_campaign, and give that number to the person when you ask them to confirm.

Input parameters:

- `id` (string, required): Campaign identifier.
- `to` (array): Optional. The addresses to restrict the send to. Omitted = the campaign's whole audience.

### `send_campaign` (~145 tokens)

Send a campaign

⚠️ IRREVERSIBLE. Locks the recipient list and triggers sending to ALL active subscribers in the workspace — or, with `to`, only to the requested addresses that are active subscribers (never an unsubscribed or suppressed address). A sent email cannot be recalled. First call preview_campaign_send with the same parameters, then ask the person for explicit confirmation, telling them how many people will receive the message. Messages go out progressively; get_campaign_stats tracks progress.

Input parameters:

- `id` (string, required): Campaign identifier.
- `to` (array): Optional. Restricts the send to these addresses. An empty list sends to nobody (refused); for the whole list, omit the field.

### `get_campaign_stats` (~94 tokens)

Campaign statistics

Status and figures for a campaign: recipients, sent, delivered, opened, clicked, bounced, complained. Rates are calculated on delivered messages, not on recipients. Every rate comes twice: open_rate and click_rate include bots (security gateways, preloads), human_open_rate and human_click_rate set them aside — that is the figure to give the person when they ask how many read it.

Input parameters:

- `id` (string, required)

### `get_email` (~60 tokens)

Sent email status

Status of an email sent via send_email: sent, delivered, bounced, or complained. Amazon's delivery callback arrives a few seconds to a few minutes after sending — a "sent" status right after the call is normal.

Input parameters:

- `id` (string, required)

## Diagnostics

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

## Score history

- 2026-09-25: 76
- 2026-09-24: 77
- 2026-09-23: 76
- 2026-09-22: 76

## Common questions

### What is the Mailcheer MCP server?

Mailcheer is an MCP server listed in the public MCP registry as com.mailcheer/mailcheer. Manage a Mailcheer email workspace: subscribers, segments, campaigns, transactional sends and stats. This page covers its hosted endpoint (https://mailcheer.com/api/mcp).

### Is the Mailcheer MCP server safe to use?

Mailcheer scores 76 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 Mailcheer MCP server expose?

Mailcheer exposes 13 tools: send_email, get_account, list_subscribers, add_subscriber, remove_subscriber, and 8 more. Their descriptions and schemas cost roughly 1,630 tokens of context every time the server is loaded.

### Does the Mailcheer MCP server require authentication?

Yes. Mailcheer 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 Mailcheer MCP server still maintained?

Mailcheer is still listed as active in the MCP registry. We last reached this channel on 25 September 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://mailcheer.com/api/mcp
- Authorisation metadata: https://mailcheer.com/.well-known/oauth-protected-resource/api/mcp
- Website: https://mailcheer.com/docs/api
- Changelog RSS feed: https://verifymcp.io/servers/com-mailcheer-mailcheer/api-mcp.xml
- Changelog JSON feed: https://verifymcp.io/servers/com-mailcheer-mailcheer/api-mcp.json
- HTML version of this page: https://verifymcp.io/servers/com-mailcheer-mailcheer/api-mcp