Thirteen email platforms checked on the vendor’s own documentation: is there a first-party MCP server, is it hosted, how do you sign in, which plans include it, and what an agent is allowed to do once connected.
by Alkan Balkaya · Last updated: 2026-10-17The best email marketing platform with MCP support for most growing businesses is Mailsoftly: a hosted MCP server at app.mailsoftly.com/mcp with OAuth sign-in and 139 documented tools, included on every plan including Free, listed in both the Claude and ChatGPT directories, with sending kept as a separate permission a person grants. Klaviyo is the strongest choice for e-commerce stores already on it, because its remote server can create and send campaigns. ActiveCampaign fits teams that live in its automation builder and are on a paid plan. MailerLite is the lowest-cost entry with a hosted server and draft-only sending. Mailchimp, Constant Contact and GetResponse have no first-party MCP server for their marketing accounts at the time of writing.
Every row below comes from the vendor’s own developer documentation, help center or product page, fetched in October 2026. Where a vendor does not state something (a plan requirement, whether the agent can send), the table says so instead of guessing. If you only want the connection steps for Mailsoftly, jump to the email for AI agents page.
New here? Start with our primer on Email Platform Comparisons for the fundamentals, then come back to this guide.
Quick context: Mailsoftly starts free with your Google or Microsoft account, 500 contacts and 2,000 emails a month, and the MCP server and API are on every plan. Paid plans start at $19 a month for 1,000 contacts ($15 on annual billing).
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Key Takeaways
MCP support means the platform runs a Model Context Protocol server that exposes its account actions (create a list, draft a campaign, read a report) as tools an AI assistant can call. The Model Context Protocol is the open standard Claude, ChatGPT, Cursor, Claude Code and Codex use to talk to outside software, so one server serves every assistant.
Three details separate a usable server from a checkbox. First, hosting: a remote server you connect by URL works from the Claude app or ChatGPT; a local package needs Node.js on your machine and an API key in a config file. Second, sign-in: OAuth means the assistant never sees a long-lived secret and you can revoke it from the account; a pasted token is a credential you now manage. Third, scope: which actions exist, and which ones (sending, deleting) ask a human first. The comparison below scores each platform on exactly those three things.
Ten platforms publish a first-party server. The table lists what each vendor documents as of October 2026. “Not stated” means the vendor page does not say, which is itself worth knowing before you connect a production account.
| Platform | First-party MCP server | Hosted and sign-in | Plans that include it | What the agent can do |
|---|---|---|---|---|
| Mailsoftly | Yes, app.mailsoftly.com/mcp, 139 tools | Hosted, OAuth 2.1, Claude and ChatGPT directories | Every plan, including Free | Contacts, lists, segments, templates, campaigns, automations, forms, landing pages, reports, domain authentication; sending is a separate permission |
| Klaviyo | Yes, mcp.klaviyo.com/mcp plus a local server | Hosted, OAuth; Owner, Admin or Manager role | All customers (vendor statement) | Create and send campaigns, flows, lists and segments, profiles, templates, reporting |
| ActiveCampaign | Yes, URL under Settings and Developer | Hosted; Claude connector directory and ChatGPT plugin directory | Starter, Plus, Professional, Enterprise (no free plan exists) | Build campaigns, trigger automations, update CRM records, check performance |
| HubSpot | Yes, mcp.hubspot.com | Hosted, OAuth 2.0 (2.1 planned); admin connects first | Not stated; needs the new Developer Platform | CRM objects and engagements read and write; campaigns and marketing content read-only; no marketing email tools |
| MailerLite | Yes, unique server URL from your account | Hosted, approval sign-in, no API keys | Not stated | Draft campaigns and automations, segments, subscribers, forms, analytics; campaigns stay drafts until you confirm |
| Kit | Yes, app.kit.com/mcp, 65+ tools | Hosted, OAuth | Paid plans only (Creator, Creator Pro); Free sees an upgrade prompt | Subscribers, tags, segments, broadcasts and sequences drafting, landing pages; sends need a Confirm click in Kit |
| Brevo | Yes, mcp.brevo.com/v1/brevo/mcp, 27 modules | Hosted, bearer MCP token created in API keys (no OAuth sign-in) | Not stated | Contacts and lists, email and SMS campaigns, analytics, templates, CRM deals, senders and domains, import and export |
| Omnisend | Yes, mcp.omnisend.com/mcp | Hosted, OAuth; Claude connector directory and ChatGPT plugin | Not stated | Read and analyze campaigns, automations, contacts, forms, segments and revenue; sending not described |
| beehiiv | Yes, connected from workspace settings | Hosted, OAuth | Read access for everyone; write access on paid plans | Segments, automations and monetization data; segment creation; publishing posts not yet available |
| Customer.io | Yes, mcp.customer.io/mcp (EU endpoint too) | Hosted, OAuth | Not stated | Read workspace data, create and manage automations and one-time sends, segments |
| Mailchimp | No account server; docs-search MCP and Agent skills only | Docs server needs no credential | Not applicable | Searches Mailchimp documentation; account actions go through the API or community servers |
| Constant Contact | Developer beta for a new transactional product (ctct.dev) | Hosted | Beta, 3,000 free emails | Send, schedule, suppress and report for agent-sent email; not the marketing account’s lists and campaigns |
| GetResponse | None found | Third-party connectors only | Not applicable | Zapier, Pipedream and Composio wrappers, plus a community GitHub server |
Tool counts make good headlines and poor decisions. The questions that decide whether a server is safe to point at a real list are whether you sign in or paste a secret, whether your plan actually includes the server, and what happens when the agent decides to send.
Read enough? Connect Claude or ChatGPT to a free Mailsoftly account and let it build your first list.Start free with Mailsoftly →
Mailsoftly runs a hosted MCP server at app.mailsoftly.com/mcp with OAuth 2.1 sign-in, so Claude, ChatGPT, Claude Code, Cursor, VS Code and Codex connect with one URL and no API key. The server exposes 139 documented tools across contacts, lists, segments, templates, campaigns, automations, forms, landing pages, reports and domain authentication, and it is listed in the Claude connector directory and the ChatGPT app directory. Drafting and building are open as soon as you sign in; sending is a separate permission a person grants on the consent screen, and every account’s first campaigns pass a short content review.
Where it draws lines on purpose: billing, contact export, sending infrastructure and account deletion are not exposed to agents, and destructive tools carry annotations so clients ask before they act. Developers who would rather build get the same surface through the REST API, an OpenAPI spec, a transactional email endpoint and webhooks in both directions. The MCP server and the API are included on every plan. Mailsoftly starts free with your Google or Microsoft account, and paid plans start at $19 a month for 1,000 contacts ($15 on annual billing). Setup details are on the MCP server page.
Klaviyo documents a remote server at mcp.klaviyo.com/mcp (recommended) and a local one, both with OAuth, available to users with the Owner, Admin or Manager role. The tool list is unusually complete: create_campaign and send_campaign, flow create, update and delete, lists and segments, profiles, templates, and read-only reporting for campaigns, flows, segments and forms. Klaviyo announced general availability in August 2025 and says the server is available to all customers. Klaviyo’s MCP documentation has the full tool table.
Where it falls short for teams outside retail: the platform is built around store events and profiles, pricing is by profile count (free up to 250 profiles, $30 a month at 1,000, $100 at 5,000), and a send tool with no documented second confirmation puts the safety burden on your client’s approval settings. Best for Shopify and other store teams already on Klaviyo who want an agent to run flows and reports.
ActiveCampaign publishes a first-party server whose URL lives in your account under Settings and Developer. It is listed in Claude’s connector directory and ChatGPT’s plugin directory, and the help center names Starter, Plus, Professional and Enterprise as the plans that include it. The vendor page describes building campaigns from inside the assistant, adding contacts to automations, updating CRM records and pulling performance, which matches what its automation-heavy customers need. See the ActiveCampaign MCP page.
Where it falls short: there is no free plan, so the server is never free to try beyond the 14-day trial; the public page does not say whether the agent can send or only build; and the separate Postmark MCP server (24 tools, transactional) runs locally with a server token rather than hosted with OAuth. Starter is $19 a month at 1,000 contacts and $99 at 5,000. Best for teams with a dedicated marketer who already builds multi-step automations in ActiveCampaign.
HubSpot’s remote server at mcp.hubspot.com is generally available and uses OAuth 2.0 today with a move to OAuth 2.1 planned. An account admin connects first through a user-level app on the new Developer Platform, then other users can connect. Coverage is CRM first: contacts, companies, deals, tickets, products, orders, quotes, lists and engagements are read and write, while campaigns, landing pages, website pages and blog posts are read-only. HubSpot’s MCP documentation lists the objects.
Where it falls short for email: marketing emails are not in the tool set, so an agent can read a campaign’s metrics but cannot draft or send a newsletter. Email sits inside Marketing Hub pricing, free for 2,000 branded emails a month, then Starter at $15 a month for 1,000 marketing contacts and about $215 at 5,000. Best for sales teams on HubSpot who want an agent working the CRM, with email handled elsewhere.
MailerLite gives each account a unique server URL and connects through an approval sign-in with no downloads, code or API keys. It appears in the connectors list in Claude and in ChatGPT’s connectors flow, and the vendor also documents Claude Code, Gemini CLI, VS Code and Cursor. The agent can draft campaigns and automations, build segments and groups, add or update subscribers, set up forms and analyze performance. MailerLite is explicit that campaigns are always drafts first and that the assistant cannot send without your confirmation, showing the audience size before you approve. Details are on the MailerLite MCP page.
Where it falls short: the page does not say which plans include the server, and the free plan was cut to 250 subscribers and 2,500 emails a month in June 2026. Paid plans start at $12 a month, about $49 at 5,000 subscribers. Best for solo operators and growing businesses who want the cheapest hosted server and are happy to press send themselves.
Kit’s AI Connectors server at app.kit.com/mcp uses OAuth and exposes more than 65 tools: reading subscribers, tags, segments, sequences, broadcasts, forms and stats; creating, tagging and unsubscribing subscribers; drafting broadcasts and sequences; editing landing pages, webhooks and templates. Sensitive actions such as scheduling a broadcast or unsubscribing return a link you must confirm inside Kit. Each connection is limited to 120 requests a minute, and access is account-level, so all users on the account share it. Kit’s connection guide covers Claude Desktop, ChatGPT in developer mode and Cursor.
Where it falls short: AI Connectors is available on paid plans only; free users can connect and see the tools, but every call returns an upgrade prompt. Creator starts at $39 a month at 1,000 subscribers and $89 at 5,000. Best for newsletter creators who already pay for Kit and want an assistant tagging and drafting for them.
Brevo’s server at mcp.brevo.com/v1/brevo/mcp bundles 27 modules, with narrower per-module endpoints if you want to limit scope: contacts and lists, email and SMS campaigns, analytics, templates, CRM deals and pipelines, senders, domains, import and export, webhooks. It works with Claude Desktop, Claude Code, Cursor, Windsurf, VS Code and Cline, some through the mcp-remote package. Brevo’s MCP documentation has the module list.
Where it falls short: access is a bearer MCP token you create in the API keys screen and paste into each client, so it is a credential to rotate and protect rather than an OAuth sign-in you revoke per app, and the page does not state a plan requirement or a sending rule. Brevo prices by email volume (free at 300 emails a day, Starter from $9 a month for 5,000 emails) with contact caps on Starter and Standard. Best for teams that already automate Brevo through its API and want the same reach from an editor.
Omnisend’s server at mcp.omnisend.com/mcp signs in with OAuth and is available as an official connector in Claude’s directory, as a ChatGPT plugin, and in Claude Code and Codex. The help center describes reading and analyzing email, SMS, A/B test and Booster campaigns, automations, contacts, forms, segments and revenue for any date range. See Omnisend’s MCP guide.
Where it falls short: the guide is about analysis, not building or sending, it does not name which plans include the server, Gemini’s web app is not supported, and Omnisend itself says the server works best with advanced or thinking models. Best for e-commerce stores on Omnisend that want revenue questions answered in chat.
beehiiv’s MCP v2, announced in April 2026, is connected from the workspace settings with OAuth and gives every account read access to podcasts, automations, segments, products, surveys, polls, referrals and monetization data. Write access arrived on all paid plans on June 16, 2026, starting with creating segments from a prompt. The vendor says drafting and publishing posts and automations are coming, so for now the agent reads and segments but does not send. The beehiiv MCP v2 announcement has the roadmap.
Where it falls short: no post publishing or sending through MCP, and write access needs a paid plan. The free Launch plan covers 2,500 subscribers with no automations; Scale is $49 a month at 1,000 subscribers and $89 at 5,000. Best for newsletter publishers who want audience insight in chat today and will wait for drafting.
Customer.io hosts a remote server at mcp.customer.io/mcp with a separate EU endpoint, signed in with OAuth. The documentation covers reading workspace data, creating and managing automations and one-time sends, and working with segments, and it recommends the Customer.io CLI instead of MCP for terminal-based tools. Customer.io’s MCP docs describe setup.
Where it falls short: the product is event-driven messaging for software teams, priced on profiles with no free plan, and the pages we checked do not state which plans include the server. Best for product and lifecycle teams who already model their users in Customer.io.
Mailchimp’s developer site offers three AI pieces: an MCP server that searches the documentation and works without a Mailchimp credential, an llms.txt index of every docs page, and Agent skills that package the Marketing API’s quirks as instructions an agent loads before calling the API. None of them act on your audiences or campaigns. A separate transactional (Mandrill) MCP server exists for developers with a server API key. The Mailchimp AI tools page lists what is official.
Where it falls short: every Mailchimp account server on the public registries is community-built and uses your API key, with no vendor support behind it. Mailchimp is free up to 250 contacts and 500 sends a month, then Essentials from $13 a month at 500 contacts and $75 at 5,000, billing for unsubscribed contacts too. Best for teams staying on Mailchimp who want an agent that reads the docs while a developer writes the integration.
Constant Contact for Agents, in developer beta at ctct.dev, is a transactional email API with an MCP server that gives an agent send, schedule, suppress and report as native tools, with 3,000 free emails to start. It is built for email an agent sends on its own behalf, and the page does not connect it to the lists and campaigns in a regular Constant Contact marketing account. The Constant Contact for Agents page describes the beta.
Where it falls short: marketing customers who want Claude to work their existing lists are left with third-party wrappers from Zapier, Composio and others. The marketing product has no free plan; Lite starts at $12 a month at 500 contacts and $80 at 5,000. Best for developers who want Constant Contact’s sending infrastructure behind an agent, not for marketers.
We found no GetResponse MCP server on its developer site or in any vendor announcement as of October 2026. Hosted wrappers from Zapier, Pipedream and Composio expose parts of its API, and a community GitHub server runs locally with an API key, none of them maintained by GetResponse. If GetResponse publishes one, this comparison will be updated with the source.
Where it falls short: an unsupported connector that drifts from the API is a liability on a production list. GetResponse has no free plan; Starter is $19 a month at 1,000 contacts and $54 at 5,000. Best for teams who are happy with Zapier as the bridge.
For platforms listed in an assistant directory (Mailsoftly, ActiveCampaign, Omnisend, MailerLite), open Claude’s Customize and Connectors screen or ChatGPT’s app directory, pick the platform, sign in and approve the scopes. For every other hosted server, add it as a custom connector by URL and complete the same sign-in. Coding agents take the URL in a config file or one command. Mailsoftly’s three most common setups:
The first call opens a browser sign-in, the server registers the client and issues a token scoped to what you approved, and the agent can start building. Granting sending is a separate step on the consent screen. The step-by-step guide with screenshots is in the help center under connecting from the assistant directory, and developers who prefer a key-based integration should read the email marketing API guide.
Monthly list prices below are from each vendor’s pricing page, verified October 2026, at 1,000 and 5,000 contacts. The MCP column repeats the plan rule so you can see where the server costs extra. Omnisend and Customer.io are not in our verified price set and are omitted rather than estimated.
| Platform | Free plan | At 1,000 contacts | At 5,000 contacts | MCP included on |
|---|---|---|---|---|
| Mailsoftly | 500 contacts, 2,000 emails a month, with your Google or Microsoft account | $19 a month, $15 on annual billing | $49 a month, $39 on annual billing | Every plan, including Free |
| Klaviyo | 250 profiles, 500 emails a month | $30 | $100 | All customers |
| ActiveCampaign | None, 14-day trial | $19 Starter | $99 Starter | All four paid plans |
| HubSpot | 2,000 emails a month with branding | $15 Starter | About $215 Starter | Not stated; CRM tools only |
| MailerLite | 250 subscribers, 2,500 emails a month | From $12 | About $49 | Not stated |
| Kit | Up to 10,000 subscribers, one automation | $39 Creator | $89 Creator | Paid plans only |
| Brevo | 300 emails a day | Priced by volume: Starter from $9 for 5,000 emails | Priced by volume with contact caps | Not stated |
| beehiiv | 2,500 subscribers, no automations | $49 Scale | $89 Scale | Read: all; write: paid |
| Mailchimp | 250 contacts, 500 sends a month | $26.50 Essentials (1,500 tier) | $75 Essentials | No account server |
| Constant Contact | None, short trial | $50 Lite | $80 Lite | Agent beta only |
| GetResponse | None | $19 Starter | $54 Starter | No server |
For the broader picture on this topic, see our complete Email Platform Comparisons guide, which covers strategy, fundamentals, and advanced playbooks.
As of October 2026: Mailsoftly, Klaviyo, ActiveCampaign, HubSpot, MailerLite, Kit, Brevo, Omnisend, beehiiv and Customer.io publish first-party MCP servers. Mailchimp offers only a documentation server and agent skills, Constant Contact has a transactional sending beta for agents, and GetResponse has none.
It means the platform exposes account actions such as creating a segment, drafting a campaign or reading a report as tools an AI assistant can call through the Model Context Protocol. One server works with Claude, ChatGPT, Cursor, Claude Code and any other MCP client, so you do not need a separate integration per assistant.
Not for your account. Mailchimp’s developer site offers an MCP server that searches its documentation without a credential, plus llms.txt and agent skills for the Marketing API. The only account-level server is for the transactional Mandrill product. Servers that manage audiences and campaigns are community projects, not supported by Mailchimp.
It depends on the vendor. Klaviyo documents a send tool. Mailsoftly makes sending a separate permission a person grants on the consent screen, and MailerLite and Kit keep campaigns as drafts until you confirm in the app. HubSpot has no marketing email tools and beehiiv cannot publish posts through MCP yet.
Mailsoftly includes the MCP server and the API on every plan, including the free plan. Kit limits it to paid plans, beehiiv gives free accounts read access only, and ActiveCampaign, Constant Contact, GetResponse and Customer.io have no free plan to begin with. Klaviyo says all customers; most other vendors do not publish a plan rule.
Yes. With OAuth the assistant receives a token scoped to the permissions you approved and you can revoke that one connection from your account. A pasted API key or MCP token is a long-lived secret that grants everything the key allows and has to be rotated if a config file leaks. Brevo is the only server in this comparison that uses a pasted token.
If the platform is in the assistant’s directory (Mailsoftly, ActiveCampaign, Omnisend, MailerLite), open Connectors in Claude or the app directory in ChatGPT, select it and sign in. Otherwise add the vendor’s server URL as a custom connector and complete the sign-in. Mailsoftly’s URL is app.mailsoftly.com/mcp.
Any hosted server with OAuth works from Cursor, Claude Code, VS Code and Codex by adding its URL to the client’s MCP config and signing in on first use. Brevo’s token-based server and local packages such as Postmark’s work too but need the key in the config file. Customer.io suggests its CLI for terminals.
Zapier, Pipedream and Composio wrap many email APIs behind their own MCP endpoints, which is the only route for Mailchimp, Constant Contact and GetResponse accounts today. Community GitHub servers run locally with your API key and are not maintained by the vendor. Both work, but neither gives you vendor support or vendor-defined safety rules.
Mailsoftly is free up to 500 contacts and $19 a month at 1,000 ($15 on annual billing) with MCP on every plan. Klaviyo is $30 at 1,000 profiles, ActiveCampaign $19 on Starter, MailerLite from $12, Kit $39 on Creator (the plan MCP requires), and beehiiv $49 on Scale. Prices are October 2026 list prices.
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