MCP server
Gmail MCP server: Claude reads your inbox, drafts the reply and files the thread
The Kasar MCP server, at https://platform.kasar.app/api/mcp/mcp, gives Claude, ChatGPT or Cursor live access to your Gmail inbox: folders, labels, unread mail, full threads. The assistant saves a draft in Gmail or sends once you confirm, and every thread tells it whether the correspondent is already in the CRM.
Facts checked on October 6, 2026
01The mailbox as it is, not a copy
The crm_mailbox tool reads Gmail at Google, at the moment you ask. It opens the inbox, starred, sent, drafts, spam, archive and your labels, which it presents as folders. It filters unread mail, pages 25 threads at a time (100 at most) and opens a whole thread, message bodies included.
That live read is not the CRM history. Kasar records part of your email on records according to rules you set; crm_inbox reads that history back, crm_mailbox reads the mailbox. Ask “what came in this morning?” and the assistant goes to the mailbox. Ask “what have we discussed with this client since March?” and it goes to the record.
crm_mailbox
- What it does with Gmail
- Lists folders and labels, threads, unread mail; opens a full thread.
- Effect on the mailbox
- None, read only
crm_draft
- What it does with Gmail
- Creates, updates, reads or deletes a draft in the Gmail Drafts folder.
- Effect on the mailbox
- A draft, never sent
crm_send_message
- What it does with Gmail
- Sends an email from the chosen account, as a reply or a new message.
- Effect on the mailbox
- Sent after preview and confirmation
crm_mark_email
- What it does with Gmail
- Marks a thread read or unread, stars or unstars it.
- Effect on the mailbox
- Changes the thread state
crm_sync_participant
- What it does with Gmail
- Adds a thread’s correspondent to the CRM and links the exchange.
- Effect on the mailbox
- None on Gmail; creates or finds the record
crm_manage_integrations
- What it does with Gmail
- Explains and changes the sync rules: mode, excluded addresses and domains, excluded subjects.
- Effect on the mailbox
- None on Gmail
crm_inbox
- What it does with Gmail
- Reads back the threads already recorded in the CRM.
- Effect on the mailbox
- None
02Gmail connects to Kasar, the assistant connects to Kasar
Two separate connections. The first links your Google account to Kasar: in the Kasar inbox, email channel, you authorise Kasar in a Google window, granting send access if you want the assistant to be able to send. That step cannot happen from the chat with the assistant. The second links the assistant to Kasar, with OAuth 2.1 and PKCE for Claude and ChatGPT, or with a key for clients installed on your computer. In ChatGPT, sending and other write actions need full MCP, in beta for Business, Enterprise and Edu plans, on the web, as of 6 October 2026; on Pro, ChatGPT reads only. The screen-by-screen walkthrough is in the Claude and Gmail tutorial.
If the Google account was connected without send access, the server returns SEND_NOT_ENABLED at preview time: reconnect the mailbox from Kasar and grant sending. With several addresses connected, the assistant names the one it reads or writes from; the send preview lists the accounts available.
An MCP key carries your own permissions on the workspaces you tick, expires after 30 days, 90 days, a year or never, as you choose, and is revoked in one click. Create one per tool: the list shows when each was last used.
03What enters the CRM, and what stays in Gmail
Ask the assistant “what are my email sync rules?” and crm_manage_integrations returns them in plain language. By default an email is recorded once you have written to that person, from any of your mailboxes. Someone who already has a record always has their email recorded, even if you never replied, so a client message is not lost. Automated senders are left out, and email with your teammates never creates a contact.
You can ask the assistant to exclude an address, a whole domain or subject keywords, or to switch to manual mode, where only what you add enters the CRM. These settings apply to email: LinkedIn and WhatsApp are set in the app.
04Five prompts to copy
- 1
“Which unread emails from this morning come from clients or prospects already in the CRM?”
crm_mailbox lists unread threads; the assistant keeps those whose status points to an existing record.
- 2
“Draft a reply to Helen’s latest message, but don’t send it.”
crm_mailbox opens the thread, crm_draft saves the reply in your Gmail Drafts, in the same thread. You polish it in Gmail.
- 3
“Send Paul the recap of our meeting from my work address.”
crm_send_message runs a preview with the sending account, recipients and subject. The send follows your go-ahead.
- 4
“Add the sender of the Bertrand Industries email to the CRM and put them in the Open quotes list.”
crm_sync_participant creates or finds the record, links the thread and adds the record to the list.
- 5
“Stop recording emails from @newsletter.example.com.”
crm_manage_integrations adds the domain to your email account’s exclusion list.
05Draft or send: two levels of trust
A draft is the safest move: the assistant writes into your Drafts folder, in the right thread, with the right reply headers, and you keep the send button in Gmail. A direct send goes through a preview showing text, recipients and sending account, then a confirmation token that lasts 5 minutes and works once. If a recipient changes between preview and send, the token is refused.
More safeguards apply. Invalid addresses are rejected at preview. Addresses on your workspace suppression list do not receive the message, and the response says so. An identical send repeated within a short window goes out once, and the server caps sends at 30 per hour per user.
Drafts for every day, sends for what you have read.
06What about Google’s own Gmail MCP server?
Google documents a remote Gmail MCP server. As of 6 October 2026 it is in Developer Preview: you need to be a member of the Google Workspace Developer Preview Program, create a Google Cloud project and set up your own OAuth client. Its tools search and read threads, create drafts and manage labels; we did not find a send tool in its list as of that date.
The Kasar server starts from another idea: the mailbox is one source among several. The same assistant reads the email, finds the record, sees the deal, yesterday’s LinkedIn exchange and last week’s meeting, then creates the follow-up task. Kasar includes one email and calendar account on Free and two mailboxes on Pro, and the MCP server comes with every plan: see pricing.
For Gmail inside Kasar without an assistant, read the Gmail integration page. Every parameter is in the messaging tools reference, and the comparison with other CRMs is in the MCP server table.
Frequently asked questions
It reads the mailbox of the account you connected to Kasar: folders, labels and threads, at the moment you ask. It does not read a colleague’s mailbox. The history recorded in the CRM follows your workspace visibility rules.
Yes. The send tool first returns a preview and a 5-minute confirmation token; the email only goes out on the second call, and the assistant is instructed to wait for your agreement before making it. If you would rather keep control, ask for a draft: it lands in your Gmail Drafts.
Both work. Kasar connects to the Google mailbox you authorise, personal Gmail or Google Workspace, with no preview programme or Google Cloud project to set up. You connect it in the Kasar inbox, email channel.
Not just because they were read. What enters the CRM depends on your sync rules. To record a specific thread, ask the assistant to add its correspondent to the CRM.
Sources
Every fact on this page can be checked on the official page below, read on the date shown.
- OpenAI, aide : Developer mode and MCP apps in ChatGPT · read on October 6, 2026
- Google for Developers, Configure the Gmail MCP server · read on October 6, 2026
- Kasar, documentation : outils MCP de messagerie · read on October 6, 2026