Enginemailer MCP by usefulapi
REMOTE · ENGINEMAILER.USEFULAPI.IO
Read Enginemailer subscribers, lists and campaigns; add subscribers, create and send campaigns.
Available components
Last scanned (1 hour ago)
Scores higher than 46% of remote servers
Reachable. Last reached 25 Oct 2026.
Category Marketing and SEO
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. How we score → Why this is hard to score →
Endpoint Security78
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- 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. View diagnostics → Pass
- HTTPS enforcement could not be verified: the plaintext port redirected somewhere other than https, so enforcement is unproven. View diagnostics → Unverified
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
- The authorisation server offers only Dynamic Client Registration (RFC 7591), which MCP 2026-07-28 deprecated in favour of Client ID Metadata Documents. View diagnostics → Partial
Transport & Reachability0
- Transport check failed: declared streamable-http, but the endpoint redirected instead of responding directly. See how to fix → View diagnostics → Fail
Schema Quality & AI Usability81
- 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).Pass
- AI-judged instruction clarity (good).Pass
- Context-footprint check failed: tool/resource definitions use about 2141 tokens (~125/item across 17 items; 17 tools + 0 resources), over budget; trim descriptions and params. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management3
- Stability observed for 1 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage93
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 78% of tool parameters carry a description.Partial
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- All 2 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation.Pass
- An AI judge read all 18 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities60
- Spec-recency check failed: implements MCP spec 2025-06-18; the latest is 2026-07-28. See how to fix → Fail
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 25 Oct 26 0
- Stability: unverified → 0.03 ▲ functional
- Server version: 1.0.1 → 1.0.3 functional
- Server version: 1.0.0 → 1.0.1 functional
- 24 Oct 26 62
First indexed and scored.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 25 Oct 2026 · Probed https://enginemailer.usefulapi.io/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=usefulapi.io | CN=WE1,O=Google Trust Services,C=US | 13 Sept 2026 | 12 Dec 2026 | ECDSA 256 | ECDSA-SHA256 | d9be3287b0fde9630e825ba1f79bff3f |
| SANs: usefulapi.io, *.usefulapi.io | ||||||
| CN=WE1,O=Google Trust Services,C=US (CA) | CN=GTS Root R4,O=Google Trust Services LLC,C=US | 13 Dec 2023 | 20 Feb 2029 | ECDSA 256 | ECDSA-SHA384 | 7ff31977972c224a76155d13b6d685e3 |
| CN=GTS Root R4,O=Google Trust Services LLC,C=US (CA) | CN=GlobalSign Root CA,OU=Root CA,O=GlobalSign nv-sa,C=BE | 15 Nov 2023 | 28 Jan 2028 | ECDSA 384 | SHA256-RSA | 7fe530bf331343bedd821610493d8a1b |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of enginemailer.usefulapi.io. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| io. | present | 38690, 57355 | 8, 8 | Verified |
| usefulapi.io. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication Enforced and verified
The endpoint asked for a token and published valid RFC 9728 metadata describing how to get one.
| Result | Enforced and verified |
|---|---|
| Enforced | On tool calls |
| HTTP status | 302 |
WWW-Authenticate challenge Bearer realm="OAuth", resource_metadata="https://enginemailer.usefulapi.io/.well-known/oauth-protected-resource/mcp"
Bearer realm="OAuth", resource_metadata="https://enginemailer.usefulapi.io/.well-known/oauth-protected-resource/mcp"Protected resource metadata
| Document | https://enginemailer.usefulapi.io/.well-known/oauth-protected-resource/mcp |
|---|---|
| Retrieved | Yes |
| Resource | https://enginemailer.usefulapi.io/mcp |
| Authorisation server | https://enginemailer.usefulapi.io |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://enginemailer.usefulapi.io/mcp | Redirected | 302 | https://usefulapi.io/enginemailer/ |
| http (plaintext) | http://enginemailer.usefulapi.io/mcp | Inconclusive | 302 | http://enginemailer.usefulapi.io/mcp |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
enginemailer_add_subscriber Add subscriber ~150
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.
| Name | Type | Req | Description |
|---|---|---|---|
| custom_fields | array | – | Custom field values to set. |
| string | yes | An email address (max 128 characters). | |
| source_type | string | – | Where the subscriber came from, e.g. 'Signup from website' (max 256). |
| subcategory_ids | array | – | Subcategory (list/segment) ids from enginemailer_list_subscriber_categories. |
No output schema declared.
No examples provided.
enginemailer_assign_campaign_recipients Assign campaign recipients ~131
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.
| Name | Type | Req | Description |
|---|---|---|---|
| audience | string | yes | – |
| campaign_id | integer | yes | Campaign id. |
| match_type | string | – | any = subscribers in at least one subcategory (OR, default); all = in every one (AND). |
| subcategory_ids | array | – | Required when audience is subcategories. |
No output schema declared.
No examples provided.
enginemailer_check_transactional_report_export Check transactional report export ~69
Status of a report export (Processing or Complete); when complete it includes the CSV download URL. POST /RESTAPI/V2/Submission/Report/CheckExport (read-only).
| Name | Type | Req | Description |
|---|---|---|---|
| export_id | integer | yes | ExportID from enginemailer_start_transactional_report_export. |
No output schema declared.
No examples provided.
enginemailer_create_campaign Create campaign (draft) ~152
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.
| Name | Type | Req | Description |
|---|---|---|---|
| content_html | string | yes | The email body, HTML (max 256 KB). |
| name | string | yes | Internal campaign name. |
| reply_to | string | – | An email address (max 128 characters). |
| sender_email | string | yes | Sender address on a verified domain. |
| sender_name | string | yes | – |
| subject | string | yes | – |
No output schema declared.
No examples provided.
enginemailer_get_campaign_stats Get campaign delivery stats ~79
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.
| Name | Type | Req | Description |
|---|---|---|---|
| campaign_id | integer | yes | Campaign id. |
No output schema declared.
No examples provided.
enginemailer_get_subscriber Get subscriber ~52
One subscriber by email: id, status and all custom field values. GET /restapi/subscriber/emsubscriber/getSubscriber.
| Name | Type | Req | Description |
|---|---|---|---|
| string | yes | An email address (max 128 characters). |
No output schema declared.
No examples provided.
enginemailer_list_campaign_categories List campaign categories ~45
The categories that campaign recipients can be filtered by (id, name, description). Needs a paid account. GET /restapi/campaign/emcampaign/GetCategoryList.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
enginemailer_list_campaign_subcategories List campaign subcategories ~75
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.
| Name | Type | Req | Description |
|---|---|---|---|
| category_id | integer | yes | Category id from enginemailer_list_campaign_categories. |
No output schema declared.
No examples provided.
enginemailer_list_campaigns List undelivered campaigns ~74
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.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
enginemailer_list_custom_fields List custom fields ~45
The subscriber custom field definitions (key, name, type). Use the keys when adding or updating subscribers. GET /restapi/subscriber/emsubscriber/getCustomField.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
enginemailer_list_subscriber_categories List subscriber categories ~83
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.
| Name | Type | Req | Description |
|---|---|---|---|
| include_active_subscriber_count | boolean | – | Also return active subscriber counts (only for accounts the vendor has enabled this for). |
No output schema declared.
No examples provided.
enginemailer_save_subscriber_category Create or update subscriber category ~119
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.
| Name | Type | Req | Description |
|---|---|---|---|
| category_id | integer | yes | 0 to create a new category, else the existing category id. |
| description | string | – | – |
| is_visible | boolean | – | Visible to subscribers (default true). |
| name | string | yes | – |
| subcategories | array | – | – |
No output schema declared.
No examples provided.
enginemailer_send_campaign Send campaign NOW ~122
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.
| Name | Type | Req | Description |
|---|---|---|---|
| campaign_id | integer | yes | Campaign id. |
| confirm | boolean | yes | Must be true: the user has approved sending this campaign to its recipients now. |
No output schema declared.
No examples provided.
enginemailer_send_transactional_email Send transactional email ~269
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.
| Name | Type | Req | Description |
|---|---|---|---|
| bcc | array | – | – |
| campaign_name | string | – | Label for reports. |
| cc | array | – | – |
| confirm | boolean | yes | Must be true: the user has approved sending this email now. |
| content_html | string | – | Email body (HTML). Not needed with template_id. |
| sender_email | string | yes | Sender address on a verified domain (must match the template's sender when template_id is used). |
| sender_name | string | – | – |
| subject | string | – | – |
| substitution_tags | array | – | Merge tags. Values must not contain { } [ ]. |
| template_id | string | – | Stored template id from the Enginemailer portal. |
| to_email | string | yes | An email address (max 128 characters). |
No output schema declared.
No examples provided.
enginemailer_start_transactional_report_export Start transactional report export ~149
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.
| Name | Type | Req | Description |
|---|---|---|---|
| domain_filter | string | – | Domain filter, sent as the vendor's DomainFilter (the sender domain in the vendor's report), e.g. example.com. |
| email_to_filter | string | – | Only emails sent to this recipient. |
| period | string | yes | Date range exactly like '1 Sep 2026 - 16 Sep 2026'. |
No output schema declared.
No examples provided.
enginemailer_unsubscribe_subscriber Unsubscribe subscriber ~68
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.
| Name | Type | Req | Description |
|---|---|---|---|
| string | yes | An email address (max 128 characters). |
No output schema declared.
No examples provided.
enginemailer_update_subscriber Update subscriber ~186
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.
| Name | Type | Req | Description |
|---|---|---|---|
| custom_fields | array | – | Custom field values to set. |
| custom_fields_mode | string | – | update_given changes only the listed fields; replace_all (the vendor default) clears the others. |
| string | yes | An email address (max 128 characters). | |
| subcategories_mode | string | – | How subcategory_ids apply (default append). |
| subcategory_ids | array | – | Subcategory (list/segment) ids from enginemailer_list_subscriber_categories. |
No output schema declared.
No examples provided.
How do I install the Enginemailer MCP by usefulapi server?
Enginemailer MCP by usefulapi is a hosted endpoint at https://enginemailer.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.
remote · enginemailer.usefulapi.io
claude mcp add --transport http io-usefulapi-enginemailer 'https://enginemailer.usefulapi.io/mcp'
What is the Enginemailer MCP by usefulapi server?
Enginemailer MCP by usefulapi is listed in the public MCP registry as io.usefulapi/enginemailer. Read Enginemailer subscribers, lists and campaigns; add subscribers, create and send campaigns. This page covers its hosted endpoint (https://enginemailer.usefulapi.io/mcp).
Is the Enginemailer MCP by usefulapi server safe to use?
Enginemailer MCP by usefulapi scores 62 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 Enginemailer MCP by usefulapi server expose?
Enginemailer MCP by usefulapi exposes 17 tools: enginemailer_get_subscriber, enginemailer_list_subscriber_categories, enginemailer_list_custom_fields, enginemailer_add_subscriber, enginemailer_update_subscriber, and 12 more. Their descriptions and schemas cost roughly 1,868 tokens of context every time the server is loaded.
Does the Enginemailer MCP by usefulapi server require authentication?
Yes. Enginemailer 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 Enginemailer MCP by usefulapi server still maintained?
Enginemailer MCP by usefulapi is still listed as active in the MCP registry. We last reached this channel on 25 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.