Claude for Outlook is the official add-in that integrates Claude into your Outlook inbox and calendar. It triages unread mail, drafts replies in your voice — landed unsent in Outlook's compose pane — and summarizes long threads with per-email citations. It is built for professionals who live in email: private equity and investment banking associates, in-house legal teams, and consultants. This guide is based on the official Anthropic help docs. (As of June 2026.)
What it can do
Claude for Outlook is in beta and available on Pro, Max, Team, and Enterprise plans.
- Inbox triage: reads unread mail and attachments and sorts into three buckets — action items for you (each with a one-line reason), items Claude can handle (pre-drafted), and noise to archive.
- Voice replies: drafts replies into Outlook's compose pane, unsent. Tone is learned from your sent folder; reply vs reply-all is chosen deliberately, and Claude warns before adding anyone new to a thread.
- Thread summaries: reads the whole conversation and reports what's decided, what's open, and who owes what — every claim cites the source email.
- Inline attachments: reads .docx, .xlsx, .pptx, and .pdf attachments on the open email without opening them (including tracked changes in Word files).
- Mailbox search: finds past conversations by topic, returning clickable citations that open the source message.
- Find time & create events: checks free/busy for calendars you can see and drafts invites into Outlook's native appointment form.
- Meeting prep: pulls the last thread and attached docs per attendee into a one-page brief.
Security: Claude never sends on its own
This is the key safety property. Claude drafts replies and invites into Outlook's native compose and appointment forms unsent — you click send. At beta the add-in does not request the Mail.Send permission, so there is no programmatic outbound sending.
Features spanning the mailbox and calendar (triage, search, find time) run through Microsoft Graph and require an IT admin to grant one-time admin consent for the Mail.ReadWrite, Calendars.Read, People.Read, User.Read, and offline_access delegated scopes (once per tenant). The Graph access token stays in the browser's MSAL cache and is never sent to Anthropic; mailbox content is fetched on demand and not persisted server-side. Chat history is stored locally in your browser (IndexedDB), not on Anthropic's servers, and isn't synced across devices.
Supported versions and install
Supported: Outlook on the web, Outlook on Windows (new and classic, Microsoft 365 subscription), Outlook on Mac (Microsoft 365 subscription).
Unsupported: Outlook 2016/2019 (perpetual/volume), Outlook on iOS and Android, and on-premises Exchange mailboxes (Exchange Online / Microsoft 365 only).
Individual install: ① open the "Claude for Outlook" listing on Microsoft AppSource → ② click "Get it now" → ③ open any email and click the Claude button in the ribbon → ④ sign in with your Claude account. Pin the task pane to keep it open as you move between messages. Admins deploy via Integrated apps, then grant the admin consent above for inbox-spanning features.
Limits and safety
As a beta feature, it is not recommended for: unattended sending (Claude never sends on its own; every draft lands unsent), client or counterparty correspondence without reading the draft, replacing your judgment on which emails matter, or privileged/regulated mailboxes without proper controls. Inputs and outputs are auto-deleted on the backend within 30 days. (Enterprise can route audit telemetry to its own OpenTelemetry collector; observability isn't available on Free, Pro, Max, or Team.)
Prompt injection risk: email bodies, signatures, and attachments from external senders are untrusted input and may hide instructions meant to manipulate Claude. Review every draft and inbox action when working with external mail. See the related browser-agent security design in the Claude in Chrome guide.
Microsoft 365 Series
Claude shares context across your Office apps. See the companion guides: Claude in Excel guide, Claude in PowerPoint guide, Claude in Word guide.
Note: This article is based on Anthropic's official help documentation (accessed June 2026). Supported versions, feature scope, and plan requirements may change. This site is not affiliated with Anthropic.