Best email marketing tools with MCP support: campaigns, automations, and analytics compared

The best email marketing tool with MCP support is Brew, because one connection lets an agent design, test, send and schedule campaigns, build and publish automations and read the results. Klaviyo and Customer.io follow for teams whose data already lives there, then Sequenzy, Resend, Loops, HubSpot, Brevo and Mailchimp.

Ranked November 2026. We re-checked each vendor's pricing page and documentation on November 1, 2026. Brew publishes this comparison, and it is a documentation comparison, not a claim of hands-on testing of every platform. Work at Klaviyo, Customer.io, Sequenzy, Resend, Loops, HubSpot, Brevo or Mailchimp? If anything here is wrong or out of date, email support@brew.new and we will correct it.

You connect your email platform's MCP server to Claude and ask for a win-back automation. Claude pulls last month's campaign report without trouble, but nothing in the tool list creates an automation, so you build the flow by hand in the dashboard.

A lot of email platforms now say they "support MCP," but what that means varies. On some platforms an agent can read reports. On others it can build a draft. On a few it can create an automation, publish it and send a campaign to your list.

This guide compares nine email platforms by what their MCP servers let an agent do, then walks through connecting Brew to Claude Code.

Key takeaways

• Sort MCP servers by the job they can finish: read analytics, draft a campaign, build an automation, or send.
• Several vendors now expose most of their API through MCP. Customer.io, Klaviyo, Brevo and Resend are examples. Most of the difference is in guardrails and in the underlying platform.
• Check the default permissions. Customer.io starts read-only. Brew requires confirmation on OAuth and organization connections; brand API-key clients need their own approval policy.
• Mailbox providers apply the same inbox rules whether you or an agent sends from your domain.

How we compared them

We read each vendor's MCP documentation on November 1, 2026 and compared them on four questions:

1. Can the agent create and send, or schedule, a campaign?
2. Can it create or edit an automation, and can it publish one?
3. Can it read campaign or automation analytics?
4. How does it authenticate, and what stops an accidental send?

We did not run the same task through each server. We only mark a tool as able to do something if its own documentation describes it.

MCP support at a glance

Brew

Brew's server is at https://brew.new/api/mcp. You connect with OAuth, choosing one brand or your whole organization, or with an API key. The tool catalog has tools in five groups:

• Design: create_email, edit_email, import_email (HTML, MJML, React Email or a Figma frame) and export_email to a connected ESP.
• Sending: send_email for tests and campaigns. It takes a scheduledAt value for scheduled sends. pause_email_send and resume_email_send hold or continue a gradual send. cancel_email_send permanently stops remaining deliveries.
• Automations: save_trigger, save_automation, test_automation, fire_trigger_event and list_automation_runs.
• Audiences and analytics: create_audience, search_contacts, get_email_analytics, and list_automations with performance data.
• Deliverability: test_email_rendering, create_inbox_placement_test and get_domain_health.

Brew's agent recipe recommends reviewing irreversible sends. OAuth and organization connections require confirmation before a live send_email; brand API-key clients need their own approval policy. Brew is also the sending platform, so the agent works with the same domains, audiences and suppression lists your team uses.

Brew ranks first because its server covers the whole job, from design to send to automation reports, on the platform that sends the email. Brew is email only. It has no SMS or push channels.

Klaviyo

Klaviyo's MCP server connects over OAuth or a private API key, either as a hosted remote server or locally. Its tool list covers campaigns, flows, templates, reporting, profiles, catalogs and more. It includes a send_campaign tool that sends a campaign to its configured audience.

Klaviyo's Claude announcement focuses on reporting, flow audits and briefs. Klaviyo fits ecommerce teams whose customer and order data already live there. Klaviyo ranks second because its tools cover campaigns, flows and reporting, including sending.

Customer.io

Customer.io's MCP server has US and EU endpoints and gives the agent access to the Journeys UI API and the Data Pipelines API. It exposes separate tools for reads (cio_read_api), writes (cio_write_api) and deletes (cio_delete_api), so you can approve each kind of action separately.

A new connection gets read scope only, and it cannot edit live data or delete people unless an admin enables that. Customer.io is multi-channel, so the same connection can reach SMS, push and in-app messages. It suits teams that already model their product data in Customer.io. It ranks third because the agent works through general read, write and delete API tools rather than a tool for each task.

Sequenzy

Sequenzy's MCP covers subscribers, lists and segments. It also drafts, edits and schedules campaigns, builds sequences with branches and wait-for-event steps, generates AI content and reads analytics. Sequenzy's docs note that some setup, billing, destructive actions and final send decisions may still need the dashboard or a human review. It answers yes to the first three questions, so it ranks fourth. That limit keeps it below Klaviyo, whose send_campaign tool sends directly, and below Customer.io, which gives separate approvals for reads, writes and deletes across more channels.

Resend

Resend's agent tooling includes a hosted MCP server at mcp.resend.com/mcp, which you authenticate with OAuth or, for headless agents, an API key. It covers sending, contacts, broadcasts, automations and templates. Resend's Automations launched in April 2026. It suits developer teams that already send transactional email through Resend. Resend ranks fifth because its server covers broadcasts, automations and metrics, but it is built for developer teams: the product events that start an automation come from your own code.

Loops

The Loops MCP server at https://mcp.loops.so manages contacts and mailing lists and sends events and published transactional emails. It also creates and manages campaigns and workflows, and it can edit email content. The docs do not list analytics. Loops fits SaaS teams that want a simple platform their agent can manage over MCP. That gap is why Loops ranks sixth.

HubSpot

HubSpot's remote server runs at mcp.hubspot.com. You create an MCP connector inside HubSpot, then connect any client that supports OAuth with PKCE. The setup documentation covers marketing email drafts through manage_marketing_email, along with CRM records. HubSpot's Fall 2026 changelog, dated September 15, 2026, adds send configuration, scheduling, publishing and post-send analytics for marketing email.

HubSpot ranks seventh because the pages we read describe no automation tools, and sending, scheduling and publishing arrived only in that changelog. It fits teams whose CRM and marketing email both already live in HubSpot.

Brevo

Brevo's MCP server combines 27 modules behind one endpoint and generates its tools from the Brevo OpenAPI spec. It covers email campaigns, contacts, CRM deals, SMS and WhatsApp campaigns, transactional templates and campaign analytics. You authenticate with a dedicated MCP key. Brevo ranks eighth because its documentation lists no automation tools, and its tools are generated from the API rather than built around email tasks.

Mailchimp

Mailchimp has two entry points for agents. Its official MCP server is for Mailchimp Transactional, the product formerly called Mandrill. A separate Claude connector works from your Mailchimp data, and Mailchimp's page describes building, refining and launching campaigns from the conversation. Check the connector's current tool list for exactly what it can save, schedule or send. Mailchimp ranks last because its official MCP server covers only Transactional email, and the connector page publishes no tool list.

How to choose

Before you give an agent write access, brief it the way you would brief a new coordinator, and send the first campaign to a seed list before the real audience.

Use the same tools from Claude Code

Add Brew's hosted server using Claude Code's HTTP MCP setup:

claude mcp add --transport http brew https://brew.new/api/mcp

Open Claude Code, run /mcp, and authenticate the Brew connection. Select the brand you intend to use. Ask Claude to call get_brew_capabilities before campaign work so it reads the current tool contract.

Start with a draft and a test recipient:

Create a product-update email for the connected brand about our new CSV import.
Link the main button to https://example.com/import.
Show me the draft, subject, sender domain, and audience before scheduling.
Send a test only to my approved test address after I provide it.

Review the preview and links, then inspect the test in your inbox. For the live send, give Claude the saved audience, exact date, time, and time zone. Review the confirmation details before approval. Save the returned send ID so you can check status or cancel the scheduled send with cancel_email_send.

For repeatable backend jobs, use a typed API client or CLI. Keep credentials in the client configuration or environment, not in prompts or committed files.

Brew's CLI guide covers terminal workflows. The MCP versus REST guide explains how to split interactive campaign work from production event handling.

Frequently asked questions

What is an MCP server for email marketing?

It is an endpoint that exposes a platform's actions as tools an AI assistant can call. Claude, ChatGPT and Cursor are common clients. The assistant reads the tool list and decides which tool to call for your request.

Can an MCP agent send a campaign without my approval?

It depends on the platform and your client settings. Brew requires confirmation for live sends on OAuth and organization connections. Brand API-key clients need their own approval policy. Customer.io starts read-only. Other servers rely on your MCP client to ask before each tool call, so check both sides.

Do I need a developer to connect one?

Usually not. Brew, Loops, Klaviyo and HubSpot support OAuth, so you paste a server URL and sign in. API keys are the fallback for clients without an OAuth screen.

Does MCP change deliverability or compliance?

No. Mailbox providers score your domain and complaint rate. Gmail's sender requirements and CAN-SPAM apply however a send was started.

Next step

The Brew MCP page has the server URL and client setup. Connect it, then ask for your next campaign as a test send.