Classify Every Inbound Email Before a Human Sees It

import express from 'express';
import { classifyAndTag } from './classifier';

const app = express();
app.use(express.json());

app.post('/webhooks/multimail', async (req, res) => {
  const { event, email_id, mailbox } = req.body;

  if (event !== 'email.received') {
    return res.sendStatus(200);
  }

  "cm">// Acknowledge immediately; classify async
  res.sendStatus(200);

  await classifyAndTag(email_id);
});

app.listen(3000);

import Anthropic from '@anthropic-ai/sdk';

const MM_API = 'https://api.multimail.dev';
const MM_TOKEN = process.env.MM_API_KEY!;
const anthropic = new Anthropic();

export async function classifyAndTag(emailId: string): Promise<void> {
  "cm">// 1. Read full email
  const emailRes = await fetch(`${MM_API}/v1/emails/${emailId}`, {
    headers: { Authorization: `Bearer ${MM_TOKEN}` },
  });
  const email = await emailRes.json();

  "cm">// 2. Classify
  const message = await anthropic.messages.create({
    model: 'claude-sonnet-4-6',
    max_tokens: 256,
    system: 'You are an email classifier. Return JSON with fields: intent (support|sales|billing|abuse|other), urgency (critical|high|normal|low), sentiment (negative|neutral|positive), topics (string[]).',
    messages: [{
      role: 'user',
      content: `Subject: ${email.subject}\n\n${email.body_text?.slice(0, 2000)}`,
    }],
  });

  const classification = JSON.parse(message.content[0].text);

  "cm">// 3. Write tags
  await fetch(`${MM_API}/v1/emails/${emailId}/tags`, {
    method: 'POST',
    headers: {
      Authorization: `Bearer ${MM_TOKEN}`,
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({
      tags: [
        `intent:${classification.intent}`,
        `urgency:${classification.urgency}`,
        `sentiment:${classification.sentiment}`,
        ...classification.topics.map((t: string) => `topic:${t}`),
      ],
    }),
  });

  console.log(`Classified ${emailId}: ${JSON.stringify(classification)}`);
}

import os
import json
import anthropic
from multimail_sdk import MultimailClient

mm = MultimailClient(api_key=os.environ["MM_API_KEY"])
ai = anthropic.Anthropic()

def classify_and_tag(email_id: str) -> dict:
    "cm"># Read full email
    email = mm.emails.get(email_id)

    "cm"># Classify
    response = ai.messages.create(
        model="claude-sonnet-4-6",
        max_tokens=256,
        system=(
            "You are an email classifier. Return JSON with: "
            "intent (support|sales|billing|abuse|other), "
            "urgency (critical|high|normal|low), "
            "sentiment (negative|neutral|positive), "
            "topics (list of strings)."
        ),
        messages=[{
            "role": "user",
            "content": f"Subject: {email.subject}\n\n{(email.body_text or &"cm">#039;')[:2000]}",
        }],
    )

    classification = json.loads(response.content[0].text)

    # Apply tags
    tags = [
        f"intent:{classification[&"cm">#039;intent']}",
        f"urgency:{classification[&"cm">#039;urgency']}",
        f"sentiment:{classification[&"cm">#039;sentiment']}",
        *[f"topic:{t}" for t in classification.get("topics", [])],
    ]
    mm.emails.tag(email_id, tags=tags)

    return classification

const res = await fetch(
  'https:"cm">//api.multimail.dev/v1/emails?tag=urgency%3Acritical&since=24h',
  {
    headers: { Authorization: `Bearer ${process.env.MM_API_KEY}` },
  }
);

const { emails } = await res.json();

for (const email of emails) {
  console.log(`[CRITICAL] ${email.subject} — from ${email.from} at ${email.received_at}`);
}

// In your MCP-connected client (Claude Desktop, Cursor, Windsurf):

// Step 1 — read the email
tool: read_email
params: { email_id: "em_01J8KXQZ4N2P3R5T7V9W" }

// Step 2 — after reviewing content, apply classification tags
tool: tag_email
params: {
  email_id: "em_01J8KXQZ4N2P3R5T7V9W",
  tags: ["intent:support", "urgency:critical", "sentiment:negative", "topic:database-outage"]
}

// Step 3 — check inbox for other critical items
tool: check_inbox
params: { tag: "urgency:critical", limit: 20 }