Connect Outlook to Claude: work accounts and Outlook.com

01Which route fits your Outlook account?

Your account type decides it. The Microsoft 365 connector needs a work account in a Microsoft Entra tenant tied to a Microsoft business plan, and personal accounts cannot connect at all.^[2] If you use Outlook.com privately, Claude needs a mailbox it can reach, which is where forwarding comes in.

Sources: Anthropic's help on the Microsoft 365 connector and custom connectors,^[1][2][3][4] Microsoft's forwarding help^[5][7] and Command Mail's documentation.^[8][9]

02What you need

For the direct route you need a Claude account on any plan and a Microsoft 365 work account with an active license. A Global Administrator in your tenant must have consented to the app once for the whole organization, and on Claude Team or Enterprise an Owner must also have added the connector for the organization.^[2] Ask IT whether both are done; without the consent, sign-in fails with an error.^[1]

For the Command Mail route you need access to Outlook's web settings. Command Mail Free covers one mailbox and the last 90 days, with reading, search, sorting and drafts but no sending. Pro adds sending, up to ten mailboxes and full history for €19 a month for the first 100 paying Pro accounts and €29 after that.^[9] Claude Free allows exactly one custom connector, so if that slot is taken you need a paid Claude plan or have to remove the other connector.^[4]

03Route 1: Connect Microsoft 365 directly

The connector covers more than mail. Claude searches SharePoint, OneDrive, Outlook mail, Calendar and Teams with the permissions you already have, so anything you cannot open in Microsoft 365 stays out of reach for Claude too.^[1]

1. Confirm with IT that tenant consent exists. A Global Administrator who has a Claude account can grant it while connecting by ticking the box to consent on behalf of the organization; without a Claude account, it is done manually in Microsoft Entra ID.^[2]
2. On Claude Team or Enterprise, an Owner opens Organization settings → Connectors, clicks + Add → All available, finds Microsoft 365 and clicks Add to your team. On Free, Pro and Max you skip this step.^[2]
3. In Claude, go to Customize → Connectors, find Microsoft 365 and click Connect.^[1]
4. Sign in with your Microsoft 365 work account. Once connected, it also works in the Claude apps for iOS and Android.^[1]
5. In a chat, open the + menu at the bottom left, hover over Connectors, turn on Microsoft 365, and start with a small read task.^[1]

A good first request: "Find the latest email in my Outlook mailbox with the subject Project plan. Give me sender, date and open questions. Don't draft or send anything."

If you only want document search, switch off the mail tools under Customize → Connectors → Microsoft 365 → Tool permissions.^[1]

04What the connector can and cannot do with Outlook mail

Without write tools, Claude only reads. By default the connector requests read permissions such as Mail.Read, Mail.Read.Shared and MailboxSettings.Read, and Claude only touches your data when a question needs it; it does not run background searches.^[1][2] Search covers your primary mailbox with its Archive folder and shared mailboxes you have delegate access to. It does not cover the separate Online Archive mailbox, so mail a retention policy moved there will not show up.^[2]

Write tools are a separate organizational decision. An Entra administrator consents to the extended permission set, which adds scopes like Mail.Send and Mail.ReadWrite, and write tools are switched on for the Claude organization; Enterprise can limit them to custom roles.^[2] Claude can then draft, send and organize email and manage categories, inbox rules and automatic replies.^[1] Sending, forwarding and sending an existing draft cannot be set to "Always allow", so you confirm every send.^[10]

Three limits matter in practice. Write tools reject sending, forwarding and drafting messages with attachments. Email that Claude sends carries a header identifying it as agent-initiated. And there are per-user limits on writes, sends and recipients, which Anthropic does not quantify.^[2] To check that write tools work, Anthropic suggests a low-risk request such as drafting an email to yourself without sending it.^[2]

05Route 2: Personal Outlook.com through Command Mail

For a personal account, set up receiving in Command Mail first and connect Claude afterwards. New mail arrives through forwarding; older mail can be brought in once by importing an export file.^[8]

1. Create your Command Mail account or sign in. Add your Outlook address in settings under Connect a mailbox and copy the private inbound address shown there.
2. Open Outlook.com in a browser and go to Settings → Mail → Forwarding and IMAP. Microsoft may ask you to sign in again before the forwarding settings appear.^[5] If two-step verification is off, Microsoft's German help page says you will be asked to turn it on first.^[11]
3. Select Enable forwarding, enter the inbound address, tick Keep a copy of forwarded messages so your Outlook mailbox stays complete, and save.^[5]
4. Send yourself a test message from another address. Command Mail shows when each mailbox last received mail.^[8]
5. Check the autonomy of the new mailbox. Without its own setting it follows the account default, and if that is unset it is auto. For a pure read test, set the mailbox to read. An agent with mail:read can still read every mailbox in your account.^[8]

Outlook marks forwarded messages as forwarded by you.^[5] Command Mail shows the sender from the message's From header. If your test message shows your own Outlook address as the sender, replace forwarding with a redirect rule in Outlook on the web: Settings → Mail → Rules → Add rule, enter a name for the rule such as Command Mail, condition Apply to all messages, action Redirect to your inbound address, then Save.^[6] Turn the plain forwarding off afterwards so nothing arrives twice.

06Work account without the connector: when forwarding is blocked

Many Microsoft 365 organizations block automatic forwarding to outside addresses. Since 2021, the default setting "Automatic - System-controlled" behaves like "Off" for new organizations and for existing ones that were not actively using it, and the original sender gets a non-delivery report with code 5.7.520.^[7]

If you see that code, talk to IT rather than working around the block with rules or third-party tools. For a work account, the Microsoft 365 connector is usually the better route anyway, because it uses the permission model your organization already runs.

07Add Command Mail to Claude

Command Mail connects to Claude as a custom connector over remote MCP. Anthropic offers custom connectors on Free, Pro, Max, Team and Enterprise, with one on Free.^[4] On Team, only Owners and Primary Owners can add custom connectors; on Enterprise, so can people with a custom role that includes Manage access to Libraries. They add Command Mail with the same details under Organization settings → Connectors. Members then find the connector under Customize → Connectors, click Connect, and skip steps 1 to 3.^[4]

1. In Claude, go to Customize → Connectors, click Add, hover over Custom and select Web.^[3]
2. Enter Command Mail as the name and https://commandmail.app/mcp as the URL. Click Continue, review the detected authentication settings, and click Continue again.^[3]
3. Under Authentication choose Sign in now, and under OAuth client keep the recommended Use Claude's published identity. You need no request header or API key. Finish with Add.^[3]
4. On Command Mail's consent screen, keep only Read and organize your mail (mail:read) for a start. Turn off drafts, sending approved drafts and mailbox setup if they are requested. Send directly, without your approval (mail:send) is off by default; leave it off.^[8]
5. Turn Command Mail on in a chat via + → Connectors and ask for capabilities first. Check account, permissions and mailboxes, then search for your test message.

A mailbox on read plus missing send permissions is not a full write lock: mail:read alone already allows label changes across the account. Phrase your first request explicitly as read-only.^[8]

08Did it work?

A connection is only useful once it returns the right account and cites the message it found. Search for a known, harmless email and compare sender, date and content with the original in Outlook. A plausible summary without a reference to a specific message is not a check.

With the Command Mail route, an older message is missing at first for a simple reason: without an import it was never there. Sending from the Outlook.com address is not possible through Command Mail, because forwarding does not make the address sendable. From Pro onward you send from a separately configured address, for example on your own domain, ideally with mail:send-approved so only the draft revision you approved goes out.^[8][9]

09Troubleshooting

Signing in to the Microsoft 365 connector fails. Check that you are using a work account rather than a personal one and that its license is active. Missing tenant-wide consent also breaks sign-in. Anthropic further points to organizational app-approval policies and to ad blockers or privacy extensions that block the sign-in popup.^[1]

"Failed to call tool". An administrator has probably revoked a single permission in Entra. You can switch the affected tool off in the connector settings, or IT can restore the permission by granting consent again.^[2]

Write tools are missing. Ask IT to confirm that the extended permission set was approved in Entra and that write tools are enabled in Claude. Then disconnect Microsoft 365 under Customize → Connectors and connect it again.^[2]

Nothing arrives in Command Mail. Check the saved forwarding setting or rule in Outlook, look for code 5.7.520 on work accounts, and compare the inbound address character by character.^[7]

10Next steps

Start with a narrow search in one mailbox before asking for summaries of whole months, and add permissions only when your workflow needs them. For Gmail, see connect Gmail to Claude; for ChatGPT, connect Outlook to ChatGPT. Permissions are explained in permissions and autonomy.

You can start Command Mail for free and then connect Claude.

Frequently asked questions

Sources

1. Anthropic: Connect to Microsoft 365 support.claude.com, accessed October 20, 2026
2. Anthropic: Set up the Microsoft 365 connector support.claude.com, accessed October 20, 2026
3. Anthropic: Use connectors to extend Claude's capabilities support.claude.com, accessed October 20, 2026
4. Anthropic: Get started with custom connectors using remote MCP support.claude.com, accessed October 20, 2026
5. Microsoft: Turn on or off automatic forwarding in Outlook.com support.microsoft.com, accessed October 20, 2026
6. Microsoft: Use rules to automatically forward messages support.microsoft.com, accessed October 20, 2026
7. Microsoft Learn: Control automatic external email forwarding learn.microsoft.com, accessed October 20, 2026
8. Command Mail: setup and permissions documentation commandmail.app, accessed October 20, 2026
9. Command Mail: plans, agent access and limits commandmail.app, accessed October 20, 2026
10. Anthropic: Microsoft 365 connector security guide support.claude.com, accessed October 20, 2026
11. Microsoft: Automatische Weiterleitung in Outlook.com (German help page) support.microsoft.com, accessed October 20, 2026