MCP server · Developer tools · official
Emailens MCP server
by emailens · official
Check your email HTML for rendering problems in Gmail, Outlook, Apple Mail and 18 more clients, right inside your AI chat.
Emailens is a helper for your AI that looks at the HTML of an email and tells you how it will actually look in different email apps. If you build or send newsletters, this saves you from the classic surprise where something looks fine on your screen but breaks in Outlook. It is made for people who write or review email code, even if they are not full-time developers.
What is an MCP server? The 30-second version
On its own, your AI can only chat with you. An MCP server is a small helper program that gives your AI a new skill or a connection to another service. This one connects your AI to Emailens, a service that checks email rendering. So when you ask your AI to look at your email, it can send the code to Emailens and bring back real answers instead of guessing.
What this MCP server does
You paste your email HTML into the chat and ask your AI to check it. Your AI passes the code to this Emailens helper, which runs it through 21 email clients and looks at the CSS. It comes back with scores per client, warnings about things that will break, and notes about dark mode, spam risk, links, images and size. Your AI then explains the results to you in plain words and can even suggest fixes. If you have an API key, it can also take real screenshots and make a shareable link.
Click to zoomWhat you can do with it
- Preview how your email renders in 21 email clients
- Get a compatibility score per client and a list of CSS problems
- Run a full quality audit including spam score, links, accessibility and dark mode
- Compare two versions of an email to see what changed
- Ask for fix instructions you can apply to your code
- Check a domain's email deliverability records (SPF, DKIM, DMARC)
- Capture real screenshots in browsers and share a preview link (needs a free API key)
Try asking your AI
- “Check this email HTML for problems in Gmail and Outlook”
- “Will my newsletter break in dark mode on Apple Mail?”
- “Compare my old and new version of this email and tell me what got better or worse”
- “Give me fix instructions for the CSS issues you found”
What it gives back to you
You get back a written summary in the chat: which clients have issues, what the problems are, and how serious they are. It also lists scores per client, and for HTML input it points to the exact lines in your code. If you use the screenshot tool, you get image links you can open. The fix tool returns markdown instructions your AI can apply to your file.
Before you start
What you need
- Node.js installed on your computer (the free software that runs the helper)
- The Claude desktop app or Claude Code, so you can add the server
- Optional: a free Emailens API key from emailens.dev if you want screenshots and share links
Good to know
The screenshot and share link tools need a free Emailens API key, and share links need a paid plan, so check the limits before relying on them.
Install it with your AI
Add Emailens MCP server to your AI, no technical skills needed
You don't install anything by hand. You copy one prompt, paste it into an AI that can work on your computer, and it checks, installs and connects the server for you, asking you when it needs something.
Sign in to get the install prompt
Members get a ready-made prompt that lets the Claude desktop app check Emailens MCP server, install it and connect it for them, step by step. You don't need any technical skills: you copy, paste and answer a few questions. Your connected AI can also find and install any of the 4,066 MCP servers here for you.
Who it's for
Email designers, marketers and developers who build or review HTML emails and want a quick sanity check before sending.
