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Enginemailer MCP by usefulapi

io.usefulapi/enginemailerusefulapi.iostreamable-httpv1.0.0Scanned

Read Enginemailer subscribers, lists and campaigns; add subscribers, create and send campaigns.

17 tools: 6 can delete or cancel things, 3 change things and 8 only read.

Tools: 6 delete, 0 irreversible, 3 write, 8 read.
  • Reads private data · 2
  • Reads text others write · 17
  • Can send data out · 2
  • 1 finding

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9 of these tools change something. Run those as governed actions.

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Tools

Grouped by what each tool does, most consequential first. Open one for its reasons and full description; descriptions are the publisher's own words.

17 tools

Deletes or cancels 6Claude Code: deny
  • enginemailer_assign_campaign_recipientsWRITE: set who a campaign will go to: all subscribers, or the subscribers in the given subcategory ids (match_type any = OR, all = AND).Reads text others writeNo findings

    Why it is in this group

    • The name "enginemailer_assign_campaign_recipients" says "assign": a word for a change.
    • The server marks it destructive (destructiveHint: true).

    What it can reach

    • untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
    Description, as the server wrote it
    WRITE: set who a campaign will go to: all subscribers, or the subscribers in the given subcategory ids (match_type any = OR, all = AND). Does not send anything. Needs a paid account. POST /restapi/campaign/emcampaign/AssignRecipientList.

    Annotations the server declares

    • title: Assign campaign recipients
    • readOnlyHint: false
    • destructiveHint: true
    • idempotentHint: true
    • openWorldHint: true
  • enginemailer_save_subscriber_categoryWRITE: create a subscriber category (category_id 0) or update one (its id), with subcategories (subcategory_id 0 creates one).Reads text others writeNo findings

    Why it is in this group

    • The name "enginemailer_save_subscriber_category" says "save": a word for a change.
    • The server marks it destructive (destructiveHint: true).

    What it can reach

    • untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
    Description, as the server wrote it
    WRITE: create a subscriber category (category_id 0) or update one (its id), with subcategories (subcategory_id 0 creates one). Names and descriptions max 128 characters. POST /restapi/subscriber/emsubscriber/updateCategory.

    Annotations the server declares

    • title: Create or update subscriber category
    • readOnlyHint: false
    • destructiveHint: true
    • idempotentHint: false
    • openWorldHint: true
  • enginemailer_send_campaignWRITE, SENDS EMAIL TO CUSTOMERS NOW and cannot be undone: delivers the campaign to its assigned recipients immediately.Reads text others writeCan send data outNo findings

    Why it is in this group

    • The name "enginemailer_send_campaign" says "send": a word for sending, and what is sent cannot be taken back.
    • The description says "cannot be undone".
    • The server marks it destructive (destructiveHint: true).

    What it can reach

    • untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
    • outboundThe name "enginemailer_send_campaign" says "send": it sends or publishes something to other people.
    Description, as the server wrote it
    WRITE, SENDS EMAIL TO CUSTOMERS NOW and cannot be undone: delivers the campaign to its assigned recipients immediately. The campaign needs at least one recipient and must not be scheduled or already delivered. Show the user the campaign and its audience and get their go-ahead first; set confirm to true only then. Needs a paid account. GET /restapi/campaign/emcampaign/SendCampaign.

    Annotations the server declares

    • title: Send campaign NOW
    • readOnlyHint: false
    • destructiveHint: true
    • idempotentHint: false
    • openWorldHint: true
  • enginemailer_send_transactional_emailWRITE, SENDS ONE EMAIL NOW and cannot be undone: submits a transactional email to one recipient (plus optional CC/BCC).Reads text others writeCan send data outNo findings

    Why it is in this group

    • The name "enginemailer_send_transactional_email" says "send": a word for sending, and what is sent cannot be taken back.
    • The description says "cannot be undone".
    • The server marks it destructive (destructiveHint: true).

    What it can reach

    • untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
    • outboundThe name "enginemailer_send_transactional_email" says "send": it sends or publishes something to other people.
    Description, as the server wrote it
    WRITE, SENDS ONE EMAIL NOW and cannot be undone: submits a transactional email to one recipient (plus optional CC/BCC). Needs a sender address on a verified domain; give either subject + content_html, or a template_id from the Enginemailer portal (the template supplies subject and sender name). Total message incl. attachments max 5 MB. Confirm the recipient and text with the user first; set confirm to true only then. POST /RESTAPI/V2/Submission/SendEmail.

    Annotations the server declares

    • title: Send transactional email
    • readOnlyHint: false
    • destructiveHint: true
    • idempotentHint: false
    • openWorldHint: true
  • enginemailer_unsubscribe_subscriberWRITE: unsubscribe a subscriber so they no longer receive campaigns.Reads text others writeNo findings

    Why it is in this group

    • The name "enginemailer_unsubscribe_subscriber" says "unsubscribe": a word for a change.
    • The server marks it destructive (destructiveHint: true).

    What it can reach

    • untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
    Description, as the server wrote it
    WRITE: unsubscribe a subscriber so they no longer receive campaigns. Reversing it needs the subscriber to opt in again in Enginemailer. GET /restapi/subscriber/emsubscriber/unSubSubscriber.

    Annotations the server declares

    • title: Unsubscribe subscriber
    • readOnlyHint: false
    • destructiveHint: true
    • idempotentHint: true
    • openWorldHint: true
  • enginemailer_update_subscriberWRITE: change an existing subscriber's subcategories and/or custom fields.Reads text others writeNo findings

    Why it is in this group

    • The name "enginemailer_update_subscriber" says "update": a word for a change.
    • The server marks it destructive (destructiveHint: true).

    What it can reach

    • untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
    Description, as the server wrote it
    WRITE: change an existing subscriber's subcategories and/or custom fields. subcategories_mode: append (default), remove (drop the given subcategories) or replace (the given list becomes the full list). custom_fields_mode: update_given (change only the given fields) or replace_all (default; fields not given are cleared). POST /restapi/subscriber/emsubscriber/updateSubscriber.

    Annotations the server declares

    • title: Update subscriber
    • readOnlyHint: false
    • destructiveHint: true
    • idempotentHint: true
    • openWorldHint: true
Changes things 3Claude Code: ask
  • enginemailer_add_subscriberWRITE: add a subscriber to the account (optionally into subcategories, with custom field values).Reads text others writeNo findings

    Why it is in this group

    • The name "enginemailer_add_subscriber" says "add": a word for a change.

    What it can reach

    • untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
    Description, as the server wrote it
    WRITE: add a subscriber to the account (optionally into subcategories, with custom field values). Only add people who consented to marketing email. Free accounts may insert 50 subscribers a day, paid accounts 10,000. POST /restapi/subscriber/emsubscriber/insertSubscriber.

    Annotations the server declares

    • title: Add subscriber
    • readOnlyHint: false
    • destructiveHint: false
    • idempotentHint: false
    • openWorldHint: true
  • enginemailer_create_campaignWRITE: create a campaign DRAFT.Reads text others writeNo findings

    Why it is in this group

    • The name "enginemailer_create_campaign" says "create": a word for a change.

    What it can reach

    • untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
    Description, as the server wrote it
    WRITE: create a campaign DRAFT. Nothing is sent: assign recipients with enginemailer_assign_campaign_recipients, then send with enginemailer_send_campaign. The sender domain must be verified in Enginemailer; max 200 campaigns per account. Needs a paid account. POST /restapi/Campaign/EMCampaign/CreateCampaign.

    Annotations the server declares

    • title: Create campaign (draft)
    • readOnlyHint: false
    • destructiveHint: false
    • idempotentHint: false
    • openWorldHint: true
  • enginemailer_start_transactional_report_exportStart a CSV export of the transactional email delivery report for a period (start date at most 60 days back).Reads text others writeNo findings

    Why it is in this group

    • The name "enginemailer_start_transactional_report_export" says "start": a word for a change.

    What it can reach

    • untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
    Description, as the server wrote it
    Start a CSV export of the transactional email delivery report for a period (start date at most 60 days back). Returns an export id; poll it with enginemailer_check_transactional_report_export. Creates a report file only; nothing is sent. POST /RESTAPI/V2/Submission/Report/Export.

    Annotations the server declares

    • title: Start transactional report export
    • readOnlyHint: false
    • destructiveHint: false
    • idempotentHint: false
    • openWorldHint: true
Only reads 8Show 8 read-only tools
  • enginemailer_check_transactional_report_exportStatus of a report export (Processing or Complete); when complete it includes the CSV download URL.Reads text others write1 finding

    Why it is in this group

    • The description's first verb is "status": a word for reading.

    What it can reach

    • untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
    • untrusted-inputThe description's first sentence says "status" and "url": it reads web pages, which anyone can write.

    Findings

    • Warn

      The description contains a 41-character base64 string.

      Matched text

      description: "...download URL. POST /RESTAPI/V2/Submission/Report/CheckExport (read-only)."

      What this check looks for
    Description, as the server wrote it
    Status of a report export (Processing or Complete); when complete it includes the CSV download URL. POST /RESTAPI/V2/Submission/Report/CheckExport (read-only).

    Annotations the server declares

    • title: Check transactional report export
    • readOnlyHint: true
    • destructiveHint: false
    • openWorldHint: true
  • enginemailer_get_campaign_statsDelivery results of a DELIVERED campaign: emails sent, delivered, bounces, opens, unique opens, clicks, unique clicks, unsubscribes, spam complaints.Reads private dataReads text others writeNo findings

    Why it is in this group

    • The name "enginemailer_get_campaign_stats" says "get": a word for reading.

    What it can reach

    • private-dataThe description's first sentence says "email": it reads mail.
    • untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
    • untrusted-inputThe description's first sentence says "email": it reads inbound email, which other people can write.
    Description, as the server wrote it
    Delivery results of a DELIVERED campaign: emails sent, delivered, bounces, opens, unique opens, clicks, unique clicks, unsubscribes, spam complaints. Needs a paid account. GET /restapi/campaign/emcampaign/getcampaigndeliverystatus.

    Annotations the server declares

    • title: Get campaign delivery stats
    • readOnlyHint: true
    • destructiveHint: false
    • openWorldHint: true
  • enginemailer_get_subscriberOne subscriber by email: id, status and all custom field values.Reads private dataReads text others writeNo findings

    Why it is in this group

    • The name "enginemailer_get_subscriber" says "get": a word for reading.

    What it can reach

    • private-dataThe description's first sentence says "email": it reads mail.
    • untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
    • untrusted-inputThe description's first sentence says "email": it reads inbound email, which other people can write.
    Description, as the server wrote it
    One subscriber by email: id, status and all custom field values. GET /restapi/subscriber/emsubscriber/getSubscriber.

    Annotations the server declares

    • title: Get subscriber
    • readOnlyHint: true
    • destructiveHint: false
    • openWorldHint: true
  • enginemailer_list_campaign_categoriesThe categories that campaign recipients can be filtered by (id, name, description).Reads text others writeNo findings

    Why it is in this group

    • The name "enginemailer_list_campaign_categories" says "list": a word for reading.

    What it can reach

    • untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
    Description, as the server wrote it
    The categories that campaign recipients can be filtered by (id, name, description). Needs a paid account. GET /restapi/campaign/emcampaign/GetCategoryList.

    Annotations the server declares

    • title: List campaign categories
    • readOnlyHint: true
    • destructiveHint: false
    • openWorldHint: true
  • enginemailer_list_campaign_subcategoriesThe subcategories of one campaign category (id, name, description); use these ids in enginemailer_assign_campaign_recipients.Reads text others writeNo findings

    Why it is in this group

    • The name "enginemailer_list_campaign_subcategories" says "list": a word for reading.

    What it can reach

    • untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
    Description, as the server wrote it
    The subcategories of one campaign category (id, name, description); use these ids in enginemailer_assign_campaign_recipients. Needs a paid account. GET /restapi/campaign/emcampaign/GetSubCategoryList.

    Annotations the server declares

    • title: List campaign subcategories
    • readOnlyHint: true
    • destructiveHint: false
    • openWorldHint: true
  • enginemailer_list_campaignsList campaigns that have NOT been delivered yet (drafts and scheduled ones): id, name, subject, sender and schedule.Reads text others writeNo findings

    Why it is in this group

    • The name "enginemailer_list_campaigns" says "list": a word for reading.

    What it can reach

    • untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
    Description, as the server wrote it
    List campaigns that have NOT been delivered yet (drafts and scheduled ones): id, name, subject, sender and schedule. Delivered campaigns are not listed by the API; use enginemailer_get_campaign_stats with a known id. Needs a paid account. GET /restapi/campaign/emcampaign/ListCampaign.

    Annotations the server declares

    • title: List undelivered campaigns
    • readOnlyHint: true
    • destructiveHint: false
    • openWorldHint: true
  • enginemailer_list_custom_fieldsThe subscriber custom field definitions (key, name, type).Reads text others writeNo findings

    Why it is in this group

    • The name "enginemailer_list_custom_fields" says "list": a word for reading.

    What it can reach

    • untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
    Description, as the server wrote it
    The subscriber custom field definitions (key, name, type). Use the keys when adding or updating subscribers. GET /restapi/subscriber/emsubscriber/getCustomField.

    Annotations the server declares

    • title: List custom fields
    • readOnlyHint: true
    • destructiveHint: false
    • openWorldHint: true
  • enginemailer_list_subscriber_categoriesThe subscriber category tree: each category with its subcategories (ids, names).Reads text others writeNo findings

    Why it is in this group

    • The name "enginemailer_list_subscriber_categories" says "list": a word for reading.

    What it can reach

    • untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
    Description, as the server wrote it
    The subscriber category tree: each category with its subcategories (ids, names). Use the subcategory ids when adding or updating subscribers and when assigning campaign recipients. GET /restapi/subscriber/emsubscriber/getSubCategory.

    Annotations the server declares

    • title: List subscriber categories
    • readOnlyHint: true
    • destructiveHint: false
    • openWorldHint: true

This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.

Exfil surface

Which tools read private data, which read text someone else can write, and which can send data out. One of each is a path a prompt injection can use.

68 paths in this server alone from private data, through text someone else wrote, to a way out. Denying 2 outbound tools breaks every one.

Reads private data2
Reads files, mail, messages, databases, secrets, calendars or repositories.
Reads text others write17
Brings in text someone else can write: web pages, inbound email, messages, issues and comments.
Can send data out2
Can carry data to people or systems: it sends, posts or publishes, or takes a recipient, channel or URL.
deny to break every path
{
  "permissions": {
    "deny": [
      "mcp__enginemailer__enginemailer_send_campaign",
      "mcp__enginemailer__enginemailer_send_transactional_email"
    ]
  }
}

Other servers in the same agent add their own tools to these paths. Audit your whole setup to see them together.

Findings

Matches of fixed checks, with the text they matched.

1 warn

History

Changes to its tool definitions and to its remote endpoint, newest first.

No change seen yet. Its tools are rescanned every day, and a remote endpoint is looked at once a week.

All changes to this server

Install

Pinned to version 1.0.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http enginemailer https://enginemailer.usefulapi.io/mcp
claude mcp add --transport http enginemailer https://enginemailer.usefulapi.io/mcp

Run in a terminal.

Claude Code permissions

Allow the reads, ask before a change or a way out, deny the deletes. Paste into .claude/settings.json.

.claude/settings.json
{
  "permissions": {
    "allow": [
      "mcp__enginemailer__enginemailer_get_subscriber",
      "mcp__enginemailer__enginemailer_list_subscriber_categories",
      "mcp__enginemailer__enginemailer_list_custom_fields",
      "mcp__enginemailer__enginemailer_list_campaigns",
      "mcp__enginemailer__enginemailer_get_campaign_stats",
      "mcp__enginemailer__enginemailer_list_campaign_categories",
      "mcp__enginemailer__enginemailer_list_campaign_subcategories",
      "mcp__enginemailer__enginemailer_check_transactional_report_export"
    ],
    "ask": [
      "mcp__enginemailer__enginemailer_add_subscriber",
      "mcp__enginemailer__enginemailer_create_campaign",
      "mcp__enginemailer__enginemailer_start_transactional_report_export"
    ],
    "deny": [
      "mcp__enginemailer__enginemailer_update_subscriber",
      "mcp__enginemailer__enginemailer_unsubscribe_subscriber",
      "mcp__enginemailer__enginemailer_save_subscriber_category",
      "mcp__enginemailer__enginemailer_assign_campaign_recipients",
      "mcp__enginemailer__enginemailer_send_campaign",
      "mcp__enginemailer__enginemailer_send_transactional_email"
    ]
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. A read that can send data out (it takes a URL, say) asks first too. It assumes the server is installed as enginemailer. Review it before you use it.

Capability tags behind 17 rules
  • mcp__enginemailer__enginemailer_get_subscriber private-data, untrusted-input
  • mcp__enginemailer__enginemailer_list_subscriber_categories untrusted-input
  • mcp__enginemailer__enginemailer_list_custom_fields untrusted-input
  • mcp__enginemailer__enginemailer_add_subscriber untrusted-input
  • mcp__enginemailer__enginemailer_update_subscriber untrusted-input
  • mcp__enginemailer__enginemailer_unsubscribe_subscriber untrusted-input
  • mcp__enginemailer__enginemailer_save_subscriber_category untrusted-input
  • mcp__enginemailer__enginemailer_list_campaigns untrusted-input
  • mcp__enginemailer__enginemailer_get_campaign_stats private-data, untrusted-input
  • mcp__enginemailer__enginemailer_list_campaign_categories untrusted-input
  • mcp__enginemailer__enginemailer_list_campaign_subcategories untrusted-input
  • mcp__enginemailer__enginemailer_create_campaign untrusted-input
  • mcp__enginemailer__enginemailer_assign_campaign_recipients untrusted-input
  • mcp__enginemailer__enginemailer_send_campaign untrusted-input, outbound
  • mcp__enginemailer__enginemailer_send_transactional_email untrusted-input, outbound
  • mcp__enginemailer__enginemailer_start_transactional_report_export untrusted-input
  • mcp__enginemailer__enginemailer_check_transactional_report_export untrusted-input

Pin

Keep the decision: fail CI when the tools change, follow every change, or show a badge.

Pin in CI

Fail a build when the tools you reviewed are not the tools the server serves today.

curl -s "https://anlyon.dev/api/v1/servers/io.usefulapi/enginemailer/verify?hash=58b99cb78ddf64bc5ef69d34998674517e12a94c8f934b4680547a6416b94e73" | jq -e '.changed == false'

Pinned hash 58b99cb78ddf, from Oct 24, 2026, 16:19 UTC.

Watch

Get told when its tools change: a new tool, a new description, a new class.

https://anlyon.dev/servers/io.usefulapi/enginemailer/changes.xml

An Atom feed. Works in any feed reader or Slack's RSS app.

Badge

anlyon.dev badge for io.usefulapi/enginemailer
[![anlyon.dev](https://anlyon.dev/badge/io.usefulapi/enginemailer.svg)](https://anlyon.dev/servers/io.usefulapi/enginemailer)

Source: MCP Registry · repository. Synced Oct 24, 2026, 17:17 UTC.