Mailcheer

com.mailcheerPublished by mailcheer.comOfficial publisherv1.1.0Updated Oct 24, 2026

Email API + newsletters. 17 MCP tools. OAuth 2.1 PKCE or API key. EU-hosted (Hetzner + SES).

VerifiedStreamable HTTPWeb executableCommunication & CollaborationBusiness & Commerce

Overview

AI-generated overview

Mailcheer is a remote email and newsletter service that lets an assistant send transactional email, manage subscribers and tags, and draft, preview and send…

What you can do
  • Send transactional email to one or more addresses and check its delivery status
  • Inspect the workspace: scopes, plan, remaining monthly emails, billing, sending domains and senders
  • List, add, update, tag, unsubscribe and erase subscribers, and manage the suppression list
  • Verify addresses before writing to them, without sending anything
  • List, create and edit draft campaigns, preview who would receive a send, and send campaigns
  • Read campaign statistics such as recipients, delivered, opened, clicked, bounced and complained
When to use it
Useful when an assistant should handle email end to end inside a Mailcheer workspace: sending transactional messages, keeping subscriber lists and tags tidy, and preparing or sending newsletters with a preview step before anything goes out.
Requirements
A remote streamable HTTP endpoint at mailcheer.com. Authentication is required: either a bearer API key in the Authorization header, created in Mailcheer under Settings > API, or an OAuth 2.1 PKCE connection, which needs no key. A Mailcheer workspace with verified sending domains is needed to send.
Before you install
The API key is a live credential granting access to the workspace; keep it secret. Several actions are irreversible: send_campaign locks the recipient list and sends to all active subscribers and cannot be recalled, erase_subscriber permanently erases a person's record, and remove_subscriber cannot be reversed through the API. Sending consumes the workspace's monthly email quota. Subscriber data and email content are handled by the Mailcheer service.

Installation

In SourceWeft

  1. Open Mailcheer in the dashboard and add it to a workspace.
  2. Connect Authorization token credentials. They are stored privately and never shown on public pages.
  3. Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/com.mailcheer%2Fmailcheer/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "mailcheer": {
      "type": "http",
      "url": "https://mailcheer.com/api/mcp",
      "headers": {
        "Authorization": "Bearer <YOUR_TOKEN>"
      }
    }
  }
}

Tools

19

send_email

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. At most 50 addresses in all, to, cc and bcc together. 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.

ParameterstorequiredfromrequiredhtmltextverifyreplyTosubjectrequiredunsubscribe_url

get_account

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.

Takes no parameters.

list_subscribers

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.

Parametersqlimitcursorstatusupdated_since

add_subscriber

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.

ParameterstagsemailrequiredlastNamefirstNamedouble_opt_in

remove_subscriber

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.

Parametersemailrequired

update_subscriber

Update a subscriber

Updates the first name (`first_name`), last name (`last_name`) and custom fields (`fields`, by technical key) of an existing subscriber. The email address cannot be changed: it is the identifier. Tags are managed with `tag_subscriber`. Unknown fields are rejected (400). The response contains the updated record and the `fields` keys that were ignored (`ignored_fields`).

Parametersemailrequiredfieldslast_namefirst_name

list_tags

List tags

The workspace's tags, with how many subscribers carry each one (`subscribers`) and, among them, the active ones (`subscribed`). Read this before tagging: reuse an existing name rather than creating a near-duplicate.

Takes no parameters.

tag_subscriber

Add or remove tags

Adds (`add`) and removes (`remove`) tags on ONE existing subscriber, and nothing else: no subscription, no confirmation email, no status touched. Prefer it to add_subscriber for changing tags: add_subscriber is a subscription and sends the confirmation again to a pending person. An unknown address is not created (404). The response says what really changed (`added`, `removed`).

Parametersaddemailrequiredremove

erase_subscriber

Erase a person (GDPR)

Erases a person from the workspace at THEIR request (right to erasure): record, name, fields, proof of consent, tags. Statistics of campaigns already sent do not move; the suppression list is not touched. To stop someone receiving anything, use remove_subscriber — not this one. IRREVERSIBLE: only use it on the explicit request of the person concerned, relayed by the user.

Parametersemailrequired

list_suppression

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.

Parametersemaillimitcursor

add_suppression

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.

Parametersemailrequiredreason

list_campaigns

List campaigns

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

Parameterslimitcursorstatus

create_campaign

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.

Parametersfromkindnamerequiredtextsubjectpreheader

update_campaign

Edit a campaign draft

Edits a DRAFT: name, subject, preheader, kind, sender, content (`text`). Nothing is sent. Prefer it to create_campaign to rework a text: otherwise the old draft stays in the list. A scheduled, sending or sent campaign cannot be edited (409).

Parametersidrequiredfromkindnametextsubjectpreheader

preview_campaign_send

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.

Parametersidrequiredto

send_campaign

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.

Parametersidrequiredto

get_campaign_stats

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.

Parametersidrequired

get_email

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.

Parametersidrequired

verify_email

Verify email addresses

Verifies one or more addresses (up to 100) BEFORE writing to them, without sending anything: syntax, a domain that receives mail, a mailbox that already hard-bounced on Mailcheer, disposable or role mailboxes, and DNS signals of a dead mailbox. Each address gets a verdict: `invalid` (writing to it will bounce), `risky` (may bounce, or is not a person), `unknown` (DNS did not answer) or `valid` (nothing known against it — not a proof that the mailbox exists). Use it before prospecting, or before importing a list you did not collect yourself.

Parametersemailsrequired

Version history

3
  1. v1.1.0LatestOct 5, 2026
  2. v1.0.1Sep 22, 2026
  3. v1.0.0Sep 22, 2026

Score

72% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 daysRequired25 pts
  • Auth declaredRequired10 pts
  • Tools listedRequired15 pts
  • DescriptionRequired15 pts
  • Logo10 pts

    Publish an icon in the registry entry.

  • Documentation15 pts

    Declare a GitHub repository with a README, or serve resource_documentation in the OAuth protected-resource metadata.

  • LicenseNot applicable

    A hosted service is used under its provider's terms, so no license is expected here. This check is left out of the percentage.