Guide

Manus AI Inbox Zero

Instead of manually sorting email, tell Manus to triage your inbox. Manus reads your unread messages, categorizes them by urgency, drafts replies for action items, and archives the rest. You review and approve. Works across all major email providers via Nylas CLI.

Written by Qasim Muhammad Staff SRE

Reviewed by Nick Barraclough

Verified — CLI 3.1.1 · Gmail, Outlook · last tested April 11, 2026

What is inbox zero with an AI agent?

Inbox zero is the practice of processing every message until your inbox is empty or near-empty. A 2024 Sanebox study found the average knowledge worker receives 126 emails per day, and roughly 62% are low-priority or automated. An AI agent like Manus handles that 62% automatically, letting you focus on the messages that actually need a human decision.

The Manus inbox-zero workflow reads unread email through the Nylas CLI, categorizes each message by urgency, drafts replies where needed, and queues low-priority messages for archiving. You review the results and approve or adjust before anything is sent or deleted.

Prerequisites

Three components are required before Manus can triage email: a Manus account with the Nylas CLI Skill, an authenticated CLI grant, and a Nylas API key. Setup takes under 5 minutes if the Skill is already installed. Without all three, the triage commands will fail with authentication errors.

  1. A Manus account with the Nylas CLI Skill installed. If you have not set up the Skill yet, follow the Manus AI Skills guide first.
  2. An authenticated Nylas CLI grant. Run nylas auth whoami in the Manus sandbox to verify. If not authenticated, run bash scripts/setup.sh.
  3. A Nylas API key from dashboard-v3.nylas.com. The free tier supports up to 5 connected accounts and works for development and testing.

The triage workflow

The Manus inbox triage follows a four-step pipeline: fetch unread messages, categorize each by urgency, draft replies for action items, and present everything for your approval. Each step maps to a Nylas CLI command that Manus executes in its sandbox. The full pipeline processes 50 messages in under 90 seconds on a typical Gmail or Outlook account.

Step 1: Fetch unread messages

Manus fetches unread email from the connected provider and returns each message as structured JSON, including sender, subject, date, and body preview. The --json flag ensures machine-readable output that Manus can parse without ambiguity. The Nylas API normalizes responses across Gmail, Outlook, and Yahoo, so the same command works regardless of provider.

nylas email list --unread --limit 50 --json

The --limit 50 flag caps each batch at 50 messages. Start with 20-50 for daily triage; larger values consume more Manus credits and may exceed the agent's context window.

Step 2: Categorize by urgency

Manus reads each message and sorts it into one of four categories:

  • Urgent — needs a response within hours (e.g., client escalation, manager request)
  • Action required — needs a response but not time-sensitive (e.g., meeting follow-up, review request)
  • FYI — informational, no response needed (e.g., newsletters, status updates)
  • Archive — noise that can be archived immediately (e.g., automated notifications, marketing)

The agent presents a summary table with sender, subject, and category for your review.

Step 3: Draft replies for action items

For messages marked "urgent" or "action required," Manus drafts replies using the Nylas CLI's AI-powered compose command. The smart-compose subcommand accepts a natural-language prompt and generates a complete email body. Manus constructs the prompt from the original message's subject, sender, and body, so each draft stays contextually relevant.

nylas email smart-compose --prompt "Reply to Sarah's budget question: confirm we'll have numbers by Friday"

Each draft is shown to you for review. Nothing is sent until you approve.

Step 4: Review and approve

You scan the categorization table and drafted replies. Adjust anything that needs a different tone or category. When ready, tell Manus to send approved replies and archive the noise. The --yes flag skips the CLI's interactive confirmation prompt, which is required because the Manus sandbox cannot handle interactive stdin. Your approval in the Manus chat is the actual human-in-the-loop check.

nylas email send --to "sarah@company.com" --subject "Re: Q4 Budget" --body "..." --yes

Example prompts

These five prompts cover the most common inbox-zero tasks: full triage, urgent-only filtering, batch reply drafting, age-based cleanup, and weekly digests. Each prompt activates the /nylas-cli Skill in Manus and maps to one or more Nylas CLI commands behind the scenes. In testing, the full triage prompt processed 50 messages in under 90 seconds on a Gmail account.

# Triage the full inbox
"Triage my inbox. Fetch unread emails, categorize each as urgent, action, FYI, or archive, and show me a summary table."

# Focus on urgent only
"Show me only urgent emails from this week. Skip newsletters and automated notifications."

# Draft replies in batch
"Draft replies for all emails that need a response. Show me each draft before sending."

# Clean up old messages
"Archive everything older than 7 days that I haven't replied to."

# Weekly digest
"Give me a weekly email digest: who emailed me most, what topics came up, and what's still waiting for a reply."

SKILL.md for inbox triage

A standalone SKILL.md file lets you define a focused triage-only Skill that runs independently from the full Nylas CLI Skill. This is useful when you want Manus to activate triage automatically on keywords like "inbox zero" or "unread email" without loading the entire CLI command set. The SKILL.md format uses YAML frontmatter for metadata and markdown for the workflow definition. According to the Manus Playbook docs, Skills with narrower scope activate faster and consume fewer tokens per invocation.

---
name: inbox-triage
description: >
  Triage unread email into urgent, action, FYI, and archive categories.
  Draft replies for action items. Summarize inbox state. Uses Nylas CLI.
  Activate when the user asks about inbox zero, triage, email cleanup,
  or unread email management.
compatibility: Requires nylas-cli skill or Nylas CLI installed.
metadata:
  author: nylas
  version: "1.0"
---

# Inbox Triage

This skill triages unread email into four categories and drafts replies.

## Workflow

1. Fetch unread messages:
   ```bash
   nylas email list --unread --limit 50 --json
   ```

2. Categorize each message:
   - **Urgent**: needs response within hours
   - **Action**: needs response, not time-sensitive
   - **FYI**: informational, no response needed
   - **Archive**: noise, safe to archive

3. Present a summary table with columns: sender, subject, category.

4. For urgent and action items, draft replies using:
   ```bash
   nylas email smart-compose --prompt "<context-specific prompt>"
   ```

5. Show all drafts for user approval before sending.

## Rules

- Never send email without explicit user approval.
- Always use `--yes` when sending to avoid interactive prompts.
- Always use `--json` for machine-readable output.
- Default to `--limit 50` unless the user specifies a different batch size.
- When in doubt about a category, ask the user.

Tips for better triage

Small adjustments to batch size, urgency rules, and prompting strategy make a measurable difference in triage quality. In testing across Gmail and Outlook accounts with 30-200 unread messages, these five practices reduced false urgency classifications by roughly 40% and cut review time from 5 minutes to under 2 minutes per session.

  • Use --limit to control batch size. Start with 20–50 emails. Larger batches use more Manus credits and may exceed context limits.
  • Be specific about urgency criteria. Tell Manus what "urgent" means for you. For example: "Anything from my manager or with the word 'deadline' is urgent."
  • Batch related requests. Instead of triaging and then separately asking for replies, do it in one prompt: "Triage my inbox and draft replies for anything urgent."
  • Run triage daily. Inbox zero works best as a daily habit. The workflow takes 2–5 minutes of review time when Manus handles the sorting.
  • Refine over time. After a few sessions, update the SKILL.md with your personal rules (e.g., "emails from sales@ are always FYI") so Manus learns your preferences.

FAQ

These three questions come up most often when developers start using Manus for inbox triage. The answers cover send safety, maintenance habits, and batch size limits based on testing with Gmail and Outlook accounts holding 30-500 unread messages.

Can Manus actually send emails on my behalf?

Manus can draft and send emails using the Nylas CLI, but the SKILL.md instructions require Manus to confirm every send with you first. You always review before anything leaves your inbox. The --yes flag only skips the CLI's interactive prompt, not user approval. According to the Manus Playbook, Skills that include a "never send without approval" rule enforce that constraint across all sessions.

How do I maintain inbox zero after the initial triage?

Run a triage pass daily. With Manus handling the sorting, each session takes 2-5 minutes of review time. Update the SKILL.md with personal rules over time, like "emails from sales@ are always FYI" or "anything from my manager is urgent." Consistent daily triage prevents backlog from building up again. Users who triage daily report staying under 10 unread messages by end of week.

How many emails can Manus triage at once?

Use the --limit flag to control batch size. Start with 20–50 emails per triage pass. Larger batches consume more Manus credits and may exceed the agent's context window, which is roughly 128K tokens. For inboxes with hundreds of unread messages, run multiple triage passes with --limit 50 each.

Next steps