Emailens MCP
REMOTE · EMAILENS.DEV · 2 COMPONENTS · SCANNED SEP 20
Analyze, audit, fix and diff HTML, MJML, Maizzle and React Email across 21 email clients.
Available components
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 Security80
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one. See how to fix → View diagnostics → Partial
- HTTPS is enforced; there's no plaintext access path. View diagnostics → Pass
- The HSTS (Strict-Transport-Security) header is present. View diagnostics → Pass
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability85
- 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
- Tool/resource definitions use about 647 tokens (~71/item across 9 items; 9 tools + 0 resources), lean.Pass
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management100
- No destabilizing schema changes in the last 30 days.Pass
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 9 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 9 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
How do I install the Emailens MCP server?
Emailens MCP is a hosted endpoint at https://emailens.dev/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.
remote · emailens.dev
claude mcp add --transport http emailens-mcp 'https://emailens.dev/api/mcp'
{
"mcpServers": {
"emailens-mcp": {
"url": "https://emailens.dev/api/mcp"
}
}
} {
"servers": {
"emailens-mcp": {
"type": "http",
"url": "https://emailens.dev/api/mcp"
}
}
} [mcp_servers.emailens-mcp] url = "https://emailens.dev/api/mcp"
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"emailens-mcp": {
"type": "remote",
"url": "https://emailens.dev/api/mcp",
"enabled": true
}
}
} openclaw mcp add emailens-mcp --url 'https://emailens.dev/api/mcp' --transport streamable-http
mcp_servers:
emailens-mcp:
url: "https://emailens.dev/api/mcp" {
"McpServers": {
"emailens-mcp": {
"Transport": "http",
"Url": "https://emailens.dev/api/mcp"
}
}
} assistant mcp add emailens-mcp -t streamable-http -u 'https://emailens.dev/api/mcp'
{
"mcpServers": {
"emailens-mcp": {
"type": "http",
"url": "https://emailens.dev/api/mcp"
}
}
} The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.
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.
- 4 Sept 26 0
- Server version: 0.7.1 → 0.8.0 functional
- 31 Aug 26 0
- Server version: 0.4.0 → 0.7.1 functional
- 26 Aug 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 25 Aug 26 0
- Stability: 0.97 → pass security
- 24 Aug 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 93 to 97. That category is still filling its 30-day observation window: 28 days of observed history at the previous scan, 29 at this one. The score rises as the window fills, whether or not the server changes.
- 11 Aug 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 31 Jul 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 30 Jul 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
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 20 Sept 2026 · Probed https://emailens.dev/api/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=emailens.dev | CN=YE2,O=Let's Encrypt,C=US | 21 Aug 2026 | 19 Nov 2026 | ECDSA 256 | ECDSA-SHA384 | 62c93355d28e161f9c5cf2a25dcf1a03958 |
| SANs: *.emailens.dev, emailens.dev | ||||||
| CN=YE2,O=Let's Encrypt,C=US (CA) | CN=Root YE,O=ISRG,C=US | 3 Sept 2025 | 2 Sept 2028 | ECDSA 384 | ECDSA-SHA384 | 4df3b15dd6c0784c507cd37b58e6f115 |
| CN=Root YE,O=ISRG,C=US (CA) | CN=ISRG Root X2,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | ECDSA 384 | ECDSA-SHA384 | 872165fc34b6e5fba8add5b3705fb53a |
| CN=ISRG Root X2,O=Internet Security Research Group,C=US (CA) | CN=ISRG Root X1,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | ECDSA 384 | SHA256-RSA | 6c8f1dc727c7117f7baf853ac980f9cd |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of emailens.dev. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| dev. | present | 60074 | 8 | Verified |
| emailens.dev. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication No authorisation required
The endpoint answered without asking for a token. Anyone who knows the URL can reach it.
| Result | No authorisation required |
|---|---|
| HTTP status | 200 |
| Header | Value |
|---|---|
| strict-transport-security | max-age=63072000; includeSubDomains |
| content-security-policy | default-src 'self'; script-src 'self' 'unsafe-inline' https://openpanel.dev; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:; media-src 'self' https://cdn.emailens.dev; font-src 'self' data:; frame-src 'self'; worker-src 'self' blob:; connect-src 'self' https://api-openpanel.philippekam.dev https://*.ingest.de.sentry.io https://*.ingest.sentry.io https://ebwqcitgedxwwrswebew.supabase.co wss://ebwqcitgedxwwrswebew.supabase.co; object-src 'none'; base-uri 'self' |
| x-content-type-options | nosniff |
| x-frame-options | SAMEORIGIN |
| referrer-policy | strict-origin-when-cross-origin |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://emailens.dev/api/mcp | Verified | 200 | |
| http (plaintext) | http://emailens.dev/api/mcp | HTTPS enforced | 308 | https://emailens.dev/api/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 →
analyze_email Analyze Email ~46
Quick CSS compatibility analysis , returns warnings and per-client scores.
| Name | Type | Req | Description |
|---|---|---|---|
| format | string | – | Input format for framework-specific fix snippets |
| html | string | yes | The email HTML source code |
No output schema declared.
No examples provided.
audit_email Audit Email ~67
Comprehensive quality audit , CSS compatibility, spam, links, accessibility, images, inbox preview, size, templates, content overflow, visual bugs.
| Name | Type | Req | Description |
|---|---|---|---|
| format | string | – | Input format |
| html | string | yes | The email HTML source code |
| skip | array | – | Checks to skip |
No output schema declared.
No examples provided.
build_email Build Email ~173
Generate a cross-client-compatible email from a brief using Emailens's self-healing loop (generate → score across 21 clients → repair). Output stays in the framework you choose. Returns a runId immediately , poll get_build_status for progress and the final code. Requires a Pro/Team API key.
| Name | Type | Req | Description |
|---|---|---|---|
| format | string | – | Output framework: 'html' (default), 'jsx', 'mjml', or 'maizzle' |
| intent | string | yes | What the email should be and contain , the brief to build from |
| maxIterations | number | – | Max repair rounds, 1-8 (default 5) |
| seedHtml | string | – | Optional existing code to improve from instead of starting blank |
| threshold | number | – | Target compatibility score, 50-100 (default 90) |
No output schema declared.
No examples provided.
check_deliverability Check Deliverability ~48
Check email deliverability for a domain , SPF, DKIM, DMARC, MX, BIMI.
| Name | Type | Req | Description |
|---|---|---|---|
| domain | string | yes | Domain to check (e.g. 'company.com') |
No output schema declared.
No examples provided.
diff_emails Diff Emails ~57
Compare two email HTML versions , shows score changes, fixed issues, and regressions per client.
| Name | Type | Req | Description |
|---|---|---|---|
| after | string | yes | Modified email HTML |
| before | string | yes | Original email HTML |
| format | string | – | Input format |
No output schema declared.
No examples provided.
fix_email Fix Email ~68
Generate a structured fix prompt for email compatibility issues.
| Name | Type | Req | Description |
|---|---|---|---|
| format | string | – | Input format , controls fix syntax |
| html | string | yes | The email HTML source code to fix |
| scope | string | – | Fix scope |
| selectedClientId | string | – | Client ID for scoped fixes |
No output schema declared.
No examples provided.
get_build_status Get Build Status ~50
Check a build_email run by runId , returns status, iteration, best compatibility score, and the current best source once available.
| Name | Type | Req | Description |
|---|---|---|---|
| runId | string | yes | The runId returned by build_email |
No output schema declared.
No examples provided.
list_clients List Email Clients ~49
List all 21 supported email clients with IDs, names, rendering engines, dark mode support, and deprecation status. Use the returned IDs to filter other tools like preview_email or capture_screenshots.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
preview_email Preview Email ~89
Full email compatibility preview , transforms HTML for 21 email clients, analyzes CSS, generates scores, simulates dark mode, checks inbox preview and email size.
| Name | Type | Req | Description |
|---|---|---|---|
| clients | array | – | Optional client ID filter |
| format | string | – | Input format: 'html' (default), 'jsx', 'mjml', or 'maizzle' |
| html | string | yes | The email HTML source code |
No output schema declared.
No examples provided.
What is the Emailens MCP server?
Emailens MCP is listed in the public MCP registry as io.github.emailens/mcp. Analyze, audit, fix and diff HTML, MJML, Maizzle and React Email across 21 email clients. This page covers its hosted endpoint (https://emailens.dev/api/mcp).
Is the Emailens MCP server safe to use?
Emailens MCP scores 89 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 Emailens MCP server expose?
Emailens MCP exposes 9 tools: preview_email, analyze_email, audit_email, fix_email, list_clients, and 4 more. Their descriptions and schemas cost roughly 647 tokens of context every time the server is loaded.
Does the Emailens MCP server require authentication?
No. We connected to Emailens MCP without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the Emailens MCP server still maintained?
Emailens MCP is still listed as active in the MCP registry. We last reached this channel on 20 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.