MCP MCP Server

MCP server for email compatibility analysis — preview, analyze, fix, diff, and capture screenshots across 21 email clients via Claude or any

Remote serverstreamable-http

What is the MCP MCP server?

MCP server for email compatibility analysis — preview, analyze, fix, diff, and capture screenshots across 21 email clients via Claude or any MCP-compatible tool. That is what the mcp mcp server brings to an AI assistant: the same capability, reachable through the Model Context Protocol rather than a separate app or dashboard.

The short version

The tools it exposes

The server publishes 9 tools. What each one is for:

  • preview_email — Full email compatibility preview — transforms HTML for 21 clients, analyzes CSS, generates scores, simulates dark mode, checks inbox preview and
  • analyze_email — Quick CSS compatibility analysis — returns per-client scores and warnings. Faster than audit_email when you only need CSS compatibility
  • audit_email — Comprehensive quality audit — CSS compatibility, spam scoring, link validation, accessibility, images, inbox preview, size (Gmail clipping), template
  • fix_email — Generate a structured fix prompt for compatibility issues. Returns markdown with fix instructions that the AI can apply directly
  • list_clients — List all 21 supported email clients with IDs, names, engines, and dark mode support
  • diff_emails — Compare two email HTML versions — shows score changes, fixed issues, and introduced issues per client
  • check_deliverability — Check email deliverability for a domain — SPF, DKIM, DMARC, MX, BIMI records with a score and actionable issues
  • capture_screenshots — Capture real email screenshots across 21 clients in real browsers. Screenshots are hosted on CDN
  • share_preview — Create a shareable link. Recipients see the full analysis without an account

What it needs from you

Configuration is passed through the environment: EMAILENS_API_KEY. Treat anything key-shaped as a real credential — scope it to the minimum the server needs, and rotate it if it ever lands in a shared config.

Getting it running

Because this one is hosted, setup is mostly authentication — you point your client at the endpoint and approve access. Nothing runs on your machine, so there is no runtime to keep patched.

How it compares

Among the team communication options, the useful question is rarely "what can it do" but "what does it cost you to run" — permissions, credentials, and how much of your context its toolset consumes. MCP's toolset — preview_email, analyze_email, audit_email and 6 more — is a fair guide to whether it matches your workflow. It is maintained by emailens; worth a glance at recent repository activity before you build anything load-bearing on it.

This entry was verified against MCP's own documentation before publication; SyncDev keeps the directory reviewed rather than auto-generated.

Things to watch

  • Your data travels to the provider's service, so the usual questions apply about what you send and what they retain.
  • With 9 tools registered it takes up a noticeable share of the context window; turn it off in projects that never touch MCP.
  • Missing credentials fail quietly in some clients — if no tools show up, check the environment block first.
  • Keep per-call confirmation enabled while you learn its behaviour; it is the cheapest safeguard you have.

Available tools

ToolWhat it does
preview_emailFull email compatibility preview — transforms HTML for 21 clients, analyzes CSS, generates scores, simulates dark mode, checks inbox preview and email size.
analyze_emailQuick CSS compatibility analysis — returns per-client scores and warnings. Faster than audit_email when you only need CSS compatibility.
audit_emailComprehensive quality audit — CSS compatibility, spam scoring, link validation, accessibility, images, inbox preview, size (Gmail clipping), template variables, content overflow, and visual bugs.
fix_emailGenerate a structured fix prompt for compatibility issues. Returns markdown with fix instructions that the AI can apply directly.
list_clientsList all 21 supported email clients with IDs, names, engines, and dark mode support.
diff_emailsCompare two email HTML versions — shows score changes, fixed issues, and introduced issues per client.
check_deliverabilityCheck email deliverability for a domain — SPF, DKIM, DMARC, MX, BIMI records with a score and actionable issues.
capture_screenshotsCapture real email screenshots across 21 clients in real browsers. Screenshots are hosted on CDN.
share_previewCreate a shareable link. Recipients see the full analysis without an account.

How to install the MCP MCP server

{
  "mcpServers": {
    "emailens": {
      "command": "npx",
      "args": ["-y", "@emailens/mcp"],
      "env": {
        "EMAILENS_API_KEY": "ek_live_..."
      }
    }
  }
}

Configuration as documented by the project. Restart the client after saving.

Configuration

VariableDescriptionRequired
EMAILENS_API_KEYCredential the server authenticates with.Yes

Example prompts to try

  • Use MCP to preview email.
  • Use MCP to analyze email.
  • Use MCP to audit email.

Frequently asked questions

It connects MCP to MCP-compatible AI assistants such as Claude and Cursor, exposing 9 tools (preview_email, analyze_email, audit_email, and more) that the assistant can call on your behalf. Instead of copying data back and forth by hand, the assistant works with MCP directly.