langchain-multimail

LangChain tools for MultiMail — give your LangChain agents email capabilities with graduated human oversight.

Installation

pip install langchain-multimail

Quick Start

from langchain_multimail import MultiMailToolkit
from langchain_openai import ChatOpenAI
from langchain.agents import create_tool_calling_agent, AgentExecutor
from langchain_core.prompts import ChatPromptTemplate

# Create tools
toolkit = MultiMailToolkit(api_key="mm_live_your_api_key")
tools = toolkit.get_tools()

# Create agent
llm = ChatOpenAI(model="gpt-4o")
prompt = ChatPromptTemplate.from_messages([
    ("system", "You are an email assistant. Use the MultiMail tools to help the user manage email."),
    ("human", "{input}"),
    ("placeholder", "{agent_scratchpad}"),
])
agent = create_tool_calling_agent(llm, tools, prompt)
executor = AgentExecutor(agent=agent, tools=tools, verbose=True)

# Run
executor.invoke({"input": "Check my inbox and summarize any new emails"})

Available Tools

Tool	Description
check_inbox	List recent emails in a mailbox
read_email	Read the full content of an email
send_email	Send an email (held for approval if gated)
reply_email	Reply to an existing email thread
search_contacts	Search contacts by name or email
list_pending	List emails awaiting human approval
decide_email	Approve or reject a pending email
get_thread	Get all emails in a conversation
tag_email	Add key-value tags to an email

This toolkit complements MultiMail's 38 MCP tools with LangChain-native wrappers for common email workflows.

Compliance

MultiMail handles regulatory compliance at the infrastructure layer — no SDK-side code changes needed:

• EU AI Act Article 50: Every AI-sent email includes a cryptographically signed ai_generated disclosure in the X-MultiMail-Identity header
• US State Laws: Maine, New York, California, Illinois — AI disclosure built into email delivery
• CAN-SPAM: Unsubscribe headers and physical address footers on all outbound email
• Formally Verified: Lean 4 proofs of identity header tamper evidence

MultiMail handles EU AI Act Article 50 compliance at the infrastructure layer. Every AI-sent email includes signed ai_generated disclosure automatically.

See multimail.dev/use-cases/eu-ai-act-email-compliance for details.

Oversight Modes

MultiMail supports graduated oversight so your agent doesn't send unsupervised email:

• gated_all — Agent drafts, human approves everything
• gated_send — Agent reads freely, human approves outbound (default)
• monitored — Agent sends, human can review after
• autonomous — Full agent control

When a mailbox uses gated oversight, send_email returns pending_send_approval and the email waits for human review. The agent can check status with list_pending.

Using Individual Tools

from multimail import MultiMail
from langchain_multimail import CheckInboxTool, SendEmailTool

client = MultiMail("mm_live_your_api_key")

inbox = CheckInboxTool(client=client)
sender = SendEmailTool(client=client)

# Use directly
print(inbox.run({"mailbox_id": "your_mailbox_id", "limit": 5}))

Links

• MultiMail — Homepage & docs
• multimail — Base Python SDK
• MCP Server — For Claude, Cursor, and other MCP clients