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Mailjet MCP Server
for AI Agents
Connect your AI agent to StackOne's Mailjet MCP server and give it 59 MCP tools out of the box. Auth, tool execution, and security all managed.
Mailjet MCP Server
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59 Agent Actions
Create, read, update, and delete across Mailjet — and extend your agent's capabilities with custom actions.
Authentication
Agent Tool Authentication
Per-user OAuth in one call. Your Mailjet MCP server gets session-scoped tokens with zero credentials stored on your infra.
Agent Auth →
Security
Agent Protection
Every Mailjet tool response scanned for prompt injection in milliseconds — 88.7% accuracy, all running on CPU.
Prompt Injection Defense →
Performance
Max Agent Context. Min Cost.
Free up to 96% of your agent's context window to enhance reasoning and reduce cost, on every Mailjet call.
Tools Discovery →What is the Mailjet MCP Server?
A Mailjet MCP server lets AI agents read and write Mailjet data through the Model Context Protocol — Anthropic's open standard for connecting LLMs to external tools. StackOne's Mailjet MCP server ships with 59 pre-built actions, fully extensible via the Connector Builder — plus managed authentication, prompt injection defense, observability, and agent execution runtime. Connect it from MCP clients like Claude Desktop, Claude Code, Cursor, Goose, and VS Code, or from agent frameworks like OpenAI Agents SDK, LangChain, and Vercel AI SDK.
All Mailjet MCP Tools
Every action from Mailjet's API, ready for your agent. Create, read, update, and delete — scoped to exactly what you need.
Campaign Drafts
- Create Campaign Draft
Create a new marketing campaign draft (newsletter) shell to later add content to and send.
- Send Campaign Draft
Send a marketing campaign draft (newsletter) immediately to its whole target contact list.
- List Campaign Drafts
Retrieve a list of editable marketing campaign drafts (newsletters) with optional filtering.
- Get Campaign Draft
Retrieve a single editable campaign draft (newsletter) by its draft ID.
- Update Campaign Draft
Update the settings (sender, subject, target list) of an existing campaign draft.
Campaign Draft Contents
- Get Campaign Draft Content
Retrieve the email body (HTML, text, MJML) of a campaign draft.
- Update Campaign Draft Content
Add or replace the email body (HTML, text, MJML) of a campaign draft.
Campaigns
- List Campaigns
Retrieve a list of already-sent campaigns (marketing and transactional) with optional filtering.
- Get Campaign
Retrieve a single already-sent campaign record by its campaign ID.
Contact Lists
- Create Contact List
Create a new empty contact list (mailing list) on the account.
- List Contact Lists
Retrieve all contact lists on the account (not scoped to any single contact).
- Get Contact List
Retrieve a single contact list (its name, address, subscriber count) by list ID.
- Update Contact List
Rename an existing contact list, or mark it deleted/restored.
- Delete Contact List
Permanently delete a contact list by its list ID.
Contact Propertys
- Create Contact Property
Define a new account-wide custom contact field (property definition).
- Get Contact Property
Retrieve a single custom-field DEFINITION (property schema) by its ID.
- Update Contact Property
Rename or retype an existing account-wide custom-field DEFINITION.
- Delete Contact Property
Permanently delete an account-wide custom-field DEFINITION by its ID.
Contacts
- Create Contact
Create a new contact on the account (email required).
- List Contacts
Retrieve a list of contacts on the account with optional filtering.
- Get Contact
Retrieve a single contact by numeric ID or email address.
- Update Contact
Update an existing contact's display name or campaign-exclusion (suppression) setting.
Contact Datas
- Get Contact Data
Retrieve the custom-field VALUES stored on a single contact.
- Update Contact Data
Set or update the custom-field VALUES on a single contact.
Messages
- List Messages
Retrieve a list of individual processed (sent) messages with rich filtering.
- Get Message
Retrieve delivery details for a single processed message by its message ID.
Segments
- Create Segment
Create a new contact segmentation filter from a targeting expression.
- List Segments
Retrieve a list of contact segmentation filters used to dynamically target campaigns.
- Get Segment
Retrieve a single contact segmentation filter (including its expression) by ID.
- Update Segment
Update the name, description, expression, or status of a segmentation filter.
- Delete Segment
Delete a contact segmentation filter by ID (must not be in use).
Senders
- Create Sender
Register a new sender email address or whole-domain (wildcard) sender.
- List Senders
Retrieve the sender addresses and domains configured on the API key, with validation status.
- Get Sender
Retrieve a single sender (address/domain and its validation status) by sender ID.
- Update Sender
Update the display name, email type, or default flag of an existing sender.
- Delete Sender
Delete a sender from the API key by its sender ID.
Templates
- Create Template
Create a new reusable email template shell (content added separately).
- List Templates
Retrieve a list of reusable email templates with optional filtering.
- Get Template
Retrieve a single template's metadata by its template ID.
- Update Template
Update an existing template's metadata (name, purposes, categories, etc.).
- Delete Template
Permanently delete a reusable email template by its template ID.
Template Contents
- Get Template Content
Retrieve the email body (HTML, text, MJML) of a template.
- Update Template Content
Add or replace the email body (HTML, text, MJML) of a template.
Event Callbacks
- Create Event Callback
Register a new Event API callback (webhook) URL for a given message event type.
- List Event Callbacks
Retrieve the Event API callback (webhook) URLs registered on the account.
- Get Event Callback
Retrieve a single Event API callback (webhook) URL by its ID.
- Update Event Callback
Update an existing Event API callback (webhook) URL, or reactivate a suspended one.
- Delete Event Callback
Delete an Event API callback (webhook) URL by its ID.
Other (11)
- Send Email
Send one or more transactional emails to specific recipients via the Send API v3.1.
- List Contact Properties
Retrieve the account-wide custom-field DEFINITIONS (the property schema), not per-contact values.
- Get Contact's Lists
Retrieve the contact lists that ONE specific contact belongs to (with per-list subscription status).
- Get Message Information
Retrieve size, spam-score, and delivery statistics for a single message by its message ID.
- List Statistics Counters
Retrieve aggregated messaging statistics (sent, opened, clicked, bounced) grouped by source and time.
- Schedule Campaign Draft
Schedule a marketing campaign draft to be sent to its target list at a future date/time.
- Test Campaign Draft
Send a preview/test copy of a campaign draft to specific recipients before the real send.
- Manage List Contact
Subscribe, update, or unsubscribe ONE contact to/from ONE contact list (synchronous).
- Manage List Contacts (Bulk)
Upload MANY contacts to ONE contact list in one asynchronous bulk job (returns a JobID).
- Manage Contact's Lists
Subscribe or unsubscribe ONE contact across MANY contact lists in one call (contact ID in path).
- Validate Sender
Trigger validation of a sender (resend activation email or re-check domain DNS).
Mailjet AI Agent Use Cases
Connect your AI agent to Mailjet and help your team scale the marketing operations they run by hand today.
Lead Nurture Sequences
Use StackOne to connect your AI agent to your marketing automation, CRM, and email tools to automate lead nurture email sequences.
View Campaign Performance Reports
Use StackOne to connect your AI agent to your marketing automation, email, and analytics platforms to automate campaign performance reporting.
View Content Repurposing
Use StackOne to connect your AI agent to your document stores, email platforms, and messaging tools to automate content repurposing and distribution.
ViewSet Up Your Mailjet MCP Server in Minutes
One endpoint. Any framework. Your agent is talking to Mailjet in under 10 lines of code.
Agent Frameworks
JSON{
"mcpServers": {
"stackone": {
"command": "npx",
"args": [
"-y",
"mcp-remote@latest",
"https://api.stackone.com/mcp?x-account-id=<account_id>",
"--header",
"Authorization: Basic <YOUR_BASE64_TOKEN>"
]
}
}
}Platform Resources
MCP Code Mode: Keeping Tool Responses Out of Agent Context
Anthropic's code_execution processes data already in context. Custom MCP code mode keeps raw tool responses in a sandbox. 14K tokens vs 500.
11 min
Comparing BM25, TF-IDF, and Hybrid Search for MCP Tool Discovery
Benchmarking BM25, TF-IDF, and hybrid search for MCP tool discovery across 916 tools. The 80/20 TF-IDF/BM25 hybrid hits 21% Top-1 accuracy in under 1ms.
10 min
Indirect Prompt Injection Defense for MCP Tools: A Technical Guide
MCP tools that read emails, CRM records, and tickets are indirect prompt injection vectors. Here's how we built a two-tier defense that scans tool results in ~11ms.
12 min
MCP vs A2A: Architecture, Security, and When to Use Each
MCP vs A2A: what each protocol standardizes, how they differ, their shared security risks including indirect prompt injection, and when to use one, both, or a hybrid architecture.
12 min
MCP vs API: What 200+ Connector Builds Taught Us
MCP wraps APIs, it doesn't replace them. After building 200+ connectors that serve both, here's when each approach wins.
14 min read
Mailjet MCP Server FAQ
Does StackOne have a Mailjet MCP server?
Yes. StackOne offers a hosted Mailjet MCP server with 59 pre-built actions, and every action is tested and QA'd by StackOne. Connect it to Claude, Cursor, and any other MCP client, or to any agent framework through the AI Action SDK. It ships with managed agent authentication, prompt injection defense, and tool discovery with server-side execution that preserve your agent's context window and keep reasoning performance.
Mailjet MCP server vs direct API integration — what's the difference?
A Mailjet MCP server and direct API integration serve different use cases. Direct API integration is for software-to-software — backend code calling Mailjet. A Mailjet MCP server is for AI agents — MCP clients like Claude and Cursor, plus framework agents built with OpenAI, LangChain, or Vercel AI — discovering and calling Mailjet at runtime. StackOne provides both.
How does Mailjet authentication work for AI agents?
Mailjet authentication for AI agents works through a StackOne Connect Session. Create one via the dashboard or the SDK — you get an auth link and ready-to-paste config for Claude Desktop, Cursor, and other MCP clients. Your user authenticates their own Mailjet account; StackOne handles token exchange, storage, and refresh. Credentials never reach the LLM, and each user is isolated via
origin_owner_id.Are Mailjet MCP tools vulnerable to prompt injection?
Yes — Mailjet MCP tools can be vulnerable to indirect prompt injection. Any tool that reads user-written content — documents, messages, tickets, records, or free-text fields — is a potential vector. StackOne Defender scans every tool response before it enters the agent's context — regex patterns in ~1ms, then a MiniLM classifier in ~4ms. 88.7% accuracy, CPU-only.
What is the context bloat of a Mailjet agent and how do I avoid it?
Context bloat happens when Mailjet tool schemas and API responses eat your Mailjet agent's memory, preventing it from reasoning effectively. A single Mailjet query can return a massive JSON response, and connecting multiple tools compounds the problem. Tools Discovery and Code Mode reduce context bloat — loading only relevant tools per query and keeping raw responses out of the agent's context.
Can I limit which actions my Mailjet agent can access?
Yes — you can limit which actions your Mailjet agent can access directly from the StackOne dashboard. Toggle actions on or off, or restrict them to specific accounts, with no code changes to your agent. Session tokens can be scoped to exact actions so if one leaks, exposure stays contained.
Can I create custom agent actions for my Mailjet MCP server?
Yes — you can create custom agent actions for your Mailjet MCP server using Connector Builder. It's an integration agent your coding assistant (Claude Code, Cursor, or Copilot) can invoke to research Mailjet's API, generate production-ready connector YAML, test against the live API, and validate before you ship.
When should I NOT use a Mailjet MCP server?
Skip a Mailjet MCP server if your integration is purely software-to-software — direct Mailjet API integration is simpler when no AI agent is involved. For deterministic, compliance-critical operations (financial transactions, regulatory reporting), direct API gives you predictable behavior without agent-driven decision-making. MCP shines when AI agents need to dynamically discover and call Mailjet actions at runtime.
What AI frameworks and AI clients does the StackOne Mailjet MCP server support?
The StackOne Mailjet MCP server supports both. MCP clients (paste-and-go apps): Claude Desktop, Claude Code, Cursor, VS Code, Goose. Agent frameworks (code SDKs you build with): OpenAI Agents SDK, Anthropic, Vercel AI, Google ADK, CrewAI, Pydantic AI, LangChain, LangGraph, Azure AI Foundry.
Put your AI agents to work
All the tools you need to build and scale AI agent integrations, with best-in-class connectivity, execution, and security.