openapi: 3.1.0 info: title: Microsoft Exchange Exchange Online Admin Accepted Domains Mailbox Import API description: REST-based administrative API that enables a focused set of Exchange cmdlets and parameters as POST-only endpoints. Provides access to key tasks previously available through Exchange Web Services (EWS), including organization configuration, accepted domains, mailbox properties, mailbox folder permissions, and distribution group membership. Built as a complementary REST-first surface for specific administrative tasks caused by the EWS deprecation planned for October 2026. version: 2.0.0 contact: name: Microsoft Support url: https://support.microsoft.com email: support@microsoft.com license: name: Microsoft API License url: https://www.microsoft.com/en-us/legal/terms-of-use x-date-modified: '2026-03-04' servers: - url: https://outlook.office365.com/adminapi/v2.0 description: Exchange Online Admin API v2.0 endpoint security: - oauth2: [] tags: - name: Mailbox Import description: Operations for importing content into mailboxes paths: /users/{user-id}/mailboxes/{mailbox-id}/folders/{folder-id}/items/import: post: operationId: importMailboxItem summary: Microsoft Exchange Import item into folder description: Import a full-fidelity item into the specified mailbox folder. Accepts MIME content and creates the item preserving all properties and metadata. Used for mailbox migration and content copying scenarios. tags: - Mailbox Import parameters: - $ref: '#/components/parameters/UserIdParam' - $ref: '#/components/parameters/MailboxIdParam' - $ref: '#/components/parameters/FolderIdParam' requestBody: required: true content: message/rfc822: schema: type: string format: binary description: The MIME content of the item to import responses: '201': description: Successfully imported item content: application/json: schema: $ref: '#/components/schemas/MailboxItem' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '404': $ref: '#/components/responses/NotFound' components: parameters: MailboxIdParam: name: mailbox-id in: path required: true description: The unique identifier of the mailbox schema: type: string FolderIdParam: name: folder-id in: path required: true description: The unique identifier of the folder schema: type: string UserIdParam: name: user-id in: path required: true description: The unique identifier or user principal name schema: type: string responses: Forbidden: description: Forbidden content: application/json: schema: $ref: '#/components/schemas/ODataError' NotFound: description: Not found content: application/json: schema: $ref: '#/components/schemas/ODataError' Unauthorized: description: Unauthorized content: application/json: schema: $ref: '#/components/schemas/ODataError' BadRequest: description: Bad request content: application/json: schema: $ref: '#/components/schemas/ODataError' schemas: ODataError: type: object description: OData error response properties: error: type: object properties: code: type: string message: type: string innerError: type: object properties: request-id: type: string date: type: string format: date-time MailboxItem: type: object description: An item in a mailbox folder properties: id: type: string readOnly: true description: The item unique identifier itemType: type: string enum: - message - event - contact - task description: The type of mailbox item subject: type: string description: The subject of the item createdDateTime: type: string format: date-time description: When the item was created lastModifiedDateTime: type: string format: date-time description: When the item was last modified size: type: integer description: Size of the item in bytes internetMessageId: type: string description: The Internet message ID (for messages) hasAttachments: type: boolean description: Whether the item has attachments securitySchemes: oauth2: type: oauth2 description: OAuth 2.0 authorization with Microsoft identity platform flows: clientCredentials: tokenUrl: https://login.microsoftonline.com/{tenant}/oauth2/v2.0/token scopes: https://outlook.office365.com/.default: Default scope for Exchange Online Admin API