KoltrixConnect Claude
Connect Claude to your Koltrix inbox.
Add Koltrix to Claude as a custom connector, sign in once, and ask Claude about your mail in plain words: what needs a reply, what Dana said about the renewal, or a draft answer waiting in your Drafts folder. The same connector works on claude.ai and in Claude Desktop.
The server URL. This is all you paste, there is no API key.
https://mcp.koltrix.com/mcpAdd Koltrix to Claude in four steps
The server URL is https://mcp.koltrix.com/mcp. There is no API key.
- In Claude, open Settings, then Connectors, and choose Add custom connector.
- Name it Koltrix and paste https://mcp.koltrix.com/mcp as the URL.
- Click Connect. Claude opens Koltrix: sign in if you need to, choose the workspace, check the permissions and click Approve.
- In a chat, turn Koltrix on from the tools menu and ask about your mail.
On Claude Team and Enterprise plans an owner may need to add the connector for the organisation first; everyone then connects their own Koltrix account. Menu names change between plans and releases, so if yours differs, look for connectors in Claude's settings.
What Claude shows you before it connects
The first time Claude connects, Koltrix shows an approval page at app.koltrix.com with the app's name, the workspace to connect if you belong to more than one, and the permissions it asks for in plain words.
Claude asks for read, organise and draft by default. If an owner or admin has allowed assistant sending in that workspace, you also see an unticked box, Also allow sending email. Leave it unticked and the connection cannot send, whatever Claude is asked.
- The connection belongs to you, in that one workspace. To use a second workspace, connect again and choose it.
- Claude sees only the mailboxes you can open in Koltrix, checked on every call.
- You can see and revoke the connection under Connect AI apps in the Koltrix sidebar. It stops working immediately.
First things to ask Claude
Claude chooses the tools; you just ask. Each of these works with the default permissions.
Triage
Find what matters before you open the inbox.
What came in overnight that needs a reply from me?
get_inbox_summaryWhich unread conversations are from real people, not newsletters?
list_threadsget_threadList the cold pitches from this week so I can skim them in one go.
list_threadsIs there anything waiting on me for more than three days?
search_mailget_thread
Reply
Get drafts waiting in your Drafts folder, written the way you would.
Draft a reply to the latest message from Acme saying we'll ship on Friday.
search_mailcreate_draftRead the thread with Dana and draft a polite answer that asks for the signed copy.
get_threadcreate_draftDraft three short replies, one for each unread customer question, and leave them in Drafts.
list_threadscreate_draftWrite a shorter, warmer version of the draft you just made.
create_draft
Daily brief
A summary to start the day, built from your real inbox.
Give me a morning brief: unread counts, what needs a reply, anything urgent.
get_inbox_summaryget_threadSummarise yesterday's conversations by customer, one line each.
search_mailget_threadWhat changed in the Acme conversation since Monday?
search_mailget_threadEnd of day: which conversations did I leave without an answer?
get_inbox_summarysearch_mail
Cards in Claude
Anthropic documents card support (the MCP Apps extension) for Claude on the web, in Claude Desktop and on mobile. When Claude supports it, search results, conversations and drafts appear as small interactive cards instead of text, and Claude may ask you to allow the app to display a card the first time. Whether Claude draws a card is up to Claude: Koltrix offers cards only to an app that says it supports them. If you see text, nothing is wrong.
3 conversations
14 unread: Primary 6, Other 5, Cold pitches 3
- Dana Whitfield9:12 AMContract renewalCan we ship on Friday? Priya needs the date for the renewal.
- Priya RamanYesterdaySigned copy of the renewalAttached is the signed copy. Let me know once you have it.
- Northwind BillingMonYour October invoiceInvoice 2041 is ready to download.
Conversation list
Shown for search_mail, list_threads, get_inbox_summary. Five rows, then Show more.
fromsubjectsnippetlast_message_atunreadlabelsurl
Contract renewal
Conversation
Shown for get_thread. Messages as plain text, attachments listed by name and size.
fromtodatesubjecttextattachments
Draft ready for your review
- From
- [email protected]
- To
- [email protected]
- Cc
- [email protected]
- Subject
- Re: Contract renewal
Draft review
Shown for create_draft. Clicking Send is the confirmation; Discard deletes nothing. Without sending allowed it says Sending is off and offers Open in Koltrix.
draft_idfromtoccsubjectreview_url
Choose a mailbox
Drafts and replies are written from the mailbox you pick.
Mailbox picker
Shown for list_mailboxes. Your choice goes back to the conversation as a message.
emaildisplay_nameaccess
Illustrations with invented mail, drawn to match the real cards. Your app draws its own frame and follows its own light or dark theme.
What every card can and cannot do:
- Loads nothing from the internet: no fonts, images or scripts, and no network requests of its own.
- Shows everything that came from an email as plain text, so a hostile subject cannot run code or load a tracking image.
- Opens links only by asking your app, and only to Koltrix.
- Follows your app's light or dark theme.
- The only tool a card can call is the draft card's Send.
If Claude cannot connect
- Claude says Koltrix is not authorised or asks you to sign in again
The connection was revoked, expired after 30 days unused, or assistants were turned off for the workspace. Reconnect from Claude's connector settings.
- Koltrix is missing from the tools menu in a chat
Turn it on from the tools menu in the chat. A connector that is added but switched off in a chat is not used there.
- Claude cannot find a message you can see in Koltrix
Check you approved the right workspace. Koltrix searches only the workspace the connection belongs to, and only the mailboxes you can open.
- Reading works but labelling or drafting fails
You did not approve that permission. Revoke the connection and connect again, approving it.
- You see a text answer where a card should be
The app decides whether to draw cards. If you declined its prompt or your organisation turned interactive connectors off, work from the text and the links Claude gives you.
Questions about connecting Claude
Do I need an API key to connect Claude to Koltrix?
No. You paste one URL, https://mcp.koltrix.com/mcp, and sign in to Koltrix when Claude sends you there. The connection uses standard OAuth sign-in and belongs to you in one workspace.
Can Claude send email from my Koltrix account?
Only if you choose to allow it. Claude reads, searches, organises and drafts out of the box. A workspace owner or admin can turn sending on, you opt in when you connect, and Claude has to show you the recipients, subject and whole message and get your yes before it sends. Limits apply: 10 recipients, 20 sends a day per connection and 50 a day per workspace.
Does it work in Claude Desktop?
Yes. Claude Desktop uses the same connectors as claude.ai. Add Koltrix under Settings, Connectors, Add custom connector with the URL above, in either app, and sign in when asked. You do not need to edit a configuration file.
Does Koltrix see my conversations with Claude?
No. Koltrix receives only the tool calls Claude makes, such as a search or a draft. The parts of your mail Claude reads are sent to Anthropic and handled under its terms.
How do I disconnect Claude?
Revoke the connection under Connect AI apps in the Koltrix sidebar and it stops working immediately. Owners and admins can also turn assistants off for the whole workspace there.
Go deeper
Guides from the blog
- Connect Claude to Koltrix, step by stepAdd Koltrix as a custom connector in Claude, approve the permissions in plain words, and run your first read, organize and draft requests. One URL, no API key.
- Inbox triage with Claude: prompts that work and whyA three-pass method and a set of prompts for triaging a Koltrix inbox with Claude or ChatGPT, with notes on the tools underneath so you can predict the results.
- A daily inbox brief with Claude and Koltrix, under 150 wordsBuild a short, read-only morning brief from Koltrix with one saved prompt: what feeds it, a sample, how to tune it, a Monday version and what it cannot know.
- Draft replies with Claude and Koltrix Drafts that sound like youHow create_draft works, how to brief an assistant for a good first draft, make it read the thread first, match your voice, and check a draft before you send it.
- Safe sending from Claude: how the confirmation flow worksKoltrix lets an assistant send only a draft, only after an admin switch, your opt-in and your yes. See the confirmation string, the limits and every check.
Also in this guide
- ChatGPTCreate a custom connector with OAuth in ChatGPT.
- CursorOne entry in mcp.json, then sign in.
- Claude CodeOne command in your terminal, then /mcp.
- Tools referenceEvery tool, its permission, inputs and an example.
- Security and sendingPermissions, safe sending and the limits.
Related on koltrix.com
Try it on your own mail.
Add your domain, connect your assistant and ask what needs a reply. Every plan starts with a free trial, no card.