Outlook (Microsoft 365 Mail and Calendar)

Outlook (Microsoft 365 mail and calendar)

This connector reads and writes the signed-in user's Outlook mailbox and calendar through Microsoft Graph v1.0 (https://graph.microsoft.com/v1.0). It works with work or school accounts (Microsoft 365, Exchange Online) and, depending on the app registration, with personal Outlook.com accounts. Everything runs as the user who authorized the connector: the AI sees and sends exactly what that user can.

Setup (one-time, about 10 minutes)

1. Open https://entra.microsoft.com (or https://portal.azure.com) → Applications → App registrations → New registration.
2. Name it (e.g. "AnythingMCP Outlook") and choose the supported account types:
   • Accounts in this organizational directory only (single tenant): only your organisation's users can sign in. Set MICROSOFT_TENANT_ID to the Directory (tenant) ID shown on the app's Overview page (a GUID), or to your domain such as contoso.onmicrosoft.com.
   • Accounts in any organizational directory (multi-tenant): set MICROSOFT_TENANT_ID to organizations.
   • ... and personal Microsoft accounts: set MICROSOFT_TENANT_ID to common (work, school and Outlook.com accounts) or consumers (Outlook.com only). The value must match the app's account type, otherwise Microsoft refuses the sign-in (AADSTS50194 or AADSTS50020).
3. Under Redirect URI pick platform Web and enter https://cloud.anythingmcp.com/api/mcp-oauth/callback on AnythingMCP Cloud, or <your AnythingMCP URL>/api/mcp-oauth/callback when you host AnythingMCP yourself. It must match character for character (AADSTS50011 otherwise).
4. API permissions → Add a permission → Microsoft Graph → Delegated permissions: add offline_access, User.Read, Mail.ReadWrite, Mail.Send, Calendars.ReadWrite.
5. Certificates & secrets → New client secret. Copy the secret Value (not the Secret ID); it is shown once. Note its expiry date: when it expires the connector stops working until you paste a new one.
6. Paste the Application (client) ID into MICROSOFT_CLIENT_ID, the secret value into MICROSOFT_CLIENT_SECRET, the tenant value from step 2 into MICROSOFT_TENANT_ID, and install.
7. On the connector page click Authorize with Provider and sign in with the mailbox the AI should work with. The refresh token is stored encrypted and access tokens (about 1 hour) are renewed automatically.

Admin consent: these delegated permissions normally do not need an administrator, but many organisations turn off user consent. If the sign-in shows "Need admin approval" (AADSTS65001 or AADSTS90094), a tenant administrator (for example a Global Administrator or Cloud Application Administrator) opens the app registration → API permissions → Grant admin consent for <organisation> once; afterwards every user can authorize. A connector authorized by an admin still reads only the admin's own mailbox: each connector works for the account that signed in.

Scopes: offline_access User.Read Mail.ReadWrite Mail.Send Calendars.ReadWrite. offline_access is what makes Microsoft issue a refresh token; without it the connector stops an hour after authorizing. For a read-only setup, replace the scopes with offline_access User.Read Mail.Read Calendars.Read in the connector's OAuth settings, authorize again and disable the sending and writing tools.

Mail: folders are addressed by id or by a well-known name (inbox, drafts, sentitems, deleteditems, archive, junkemail). outlook_list_messages and outlook_search_messages return summaries (subject, sender, dates, bodyPreview); outlook_get_message returns one message with its body as plain text. Moving a message gives it a new id. outlook_send_mail and the reply tools send immediately; outlook_create_draft + outlook_send_draft leave room to review. Recipients are written as [{"emailAddress": {"address": "[email protected]", "name": "Ana"}}].

Search and filter: search takes a quoted keyword query, e.g. "invoice" or "from:[email protected] subject:offer", returns at most 1000 results and cannot be combined with filter or orderby. filter takes OData, e.g. isRead eq false and receivedDateTime ge 2026-10-01T00:00:00Z; a property used in orderby must also appear in filter, first, or Outlook answers InefficientFilter.

Calendar: outlook_list_events and outlook_list_calendar_events read a time range (start_date_time, end_date_time, ISO 8601 with offset) and expand recurring meetings into occurrences. Times come back in UTC unless timezone is given (Europe/Berlin or W. Europe Standard Time). Creating or updating an event with attendees sends them invitations or updates. outlook_get_free_busy checks availability of colleagues and rooms in the same organisation; it is not available for personal accounts.

Pagination: list responses carry @odata.nextLink while more results exist. Call the same tool again with the same arguments and skip set to the $skip value in that link. top sets the page size (Outlook's default is 10).

Rate limits: Microsoft Graph throttles per mailbox (Outlook allows about 10,000 requests per 10 minutes per app and mailbox, and 4 concurrent requests). A throttled call answers 429 with Retry-After.

Common errors

• 401 InvalidAuthenticationToken: the authorization was revoked or the client secret expired. Paste a new secret if needed and click Authorize with Provider again.
• 403 ErrorAccessDenied / Authorization_RequestDenied: a permission from step 4 is missing or was not consented. Add it, grant consent and authorize again.
• 404 ErrorItemNotFound: the id belongs to another mailbox, or the message was moved (its id changed).
• MailboxNotEnabledForRESTAPI: the account has no Exchange Online mailbox (for example an on-premises mailbox or an unlicensed user).

Out of scope here: deleting mail or events, attachments, contacts, mailbox rules, other users' and shared mailboxes.