> ## Documentation Index > Fetch the complete documentation index at: https://sendmux.ai/docs/llms.txt > Use this file to discover all available pages before exploring further. # Resume a mailbox > Restores a suspended mailbox so it can authenticate, receive mail, and send from the mailbox address again. The operation is idempotent and accepts `Idempotency-Key` for safe retries. ## OpenAPI ````yaml /openapi-app.json post /mailboxes/{public_id}/resume openapi: 3.1.0 info: description: Programmatic access to your Sendmux email infrastructure. title: Sendmux API version: 1.0.0 servers: - description: API v1 url: https://app.sendmux.ai/api/v1 security: - bearerAuth: [] paths: /mailboxes/{public_id}/resume: post: tags: - Mailboxes summary: Resume a mailbox description: >- Restores a suspended mailbox so it can authenticate, receive mail, and send from the mailbox address again. The operation is idempotent and accepts `Idempotency-Key` for safe retries. operationId: managementResumeMailbox parameters: - in: path name: public_id required: true schema: description: Mailbox public ID type: string - in: header name: Idempotency-Key required: false schema: description: >- Client-chosen unique key to safely retry the request. Cached for 24h per (team, endpoint, key). example: mailbox-resume-20260424-001 maxLength: 255 type: string responses: '200': content: application/json: schema: $ref: '#/components/schemas/MailboxItemResponse' description: Resumed mailbox '403': content: application/json: schema: $ref: '#/components/schemas/ApiError' description: Root API key required '404': content: application/json: schema: $ref: '#/components/schemas/ApiError' description: Mailbox not found '409': content: application/json: schema: $ref: '#/components/schemas/ApiError' description: >- Mailbox is deleted, or `Idempotency-Key` was replayed with a different request body. '503': content: application/json: schema: $ref: '#/components/schemas/ApiError' description: Mailbox service temporarily unavailable security: - bearerAuth: [] components: schemas: MailboxItemResponse: allOf: - $ref: '#/components/schemas/SuccessEnvelope' - properties: data: $ref: '#/components/schemas/Mailbox' meta: $ref: '#/components/schemas/ResponseMeta' required: - data type: object unevaluatedProperties: false ApiError: additionalProperties: false properties: error: additionalProperties: false properties: code: description: Machine-readable error code enum: - invalid_parameter - missing_parameter - authentication_required - insufficient_permissions - not_found - conflict - limit_exceeded - idempotency_conflict - payload_too_large - validation_error - rate_limit_exceeded - service_unavailable - internal_error example: invalid_parameter type: string doc_url: description: Link to relevant documentation type: string errors: description: >- Accumulated per-field issues for validation errors. Only present on 400/422 responses. items: $ref: '#/components/schemas/ApiErrorDetail' type: array message: description: Human-readable error description type: string param: description: The parameter that caused the error type: string retryable: description: >- Whether the caller may safely retry this request. 4xx are typically false (except 429); 5xx are typically true. example: false type: boolean required: - code - message - retryable type: object meta: additionalProperties: false properties: request_id: example: req_clxxxxxxxxxxxxxxxxxxxxxxxxx type: string required: - request_id type: object ok: enum: - false type: boolean required: - ok - error - meta type: object SuccessEnvelope: properties: meta: additionalProperties: {} properties: {} type: object ok: enum: - true type: boolean required: - ok - meta type: object Mailbox: additionalProperties: false properties: created_at: description: ISO 8601 creation timestamp type: string display_name: description: Optional display name shown in outbound From headers type: - string - 'null' email: description: Mailbox email address (lowercase) example: agent@acme.com type: string id: description: Public ID example: mbx_clxxxxxxxxxxxxxxxxxxxxxxxxx type: string quota_bytes: description: >- Storage quota in bytes. Current writable tiers are 1 GB, 5 GB, and 50 GB. type: - integer - 'null' send_scope: $ref: '#/components/schemas/MailboxSendScope' status: description: active | suspended | deleted example: active type: string required: - id - email - display_name - quota_bytes - send_scope - status - created_at type: object ResponseMeta: additionalProperties: false properties: request_id: example: req_clxxxxxxxxxxxxxxxxxxxxxxxxx type: string required: - request_id type: object ApiErrorDetail: additionalProperties: false properties: code: description: >- Machine-readable issue code from the validator (e.g. zod issue code). example: invalid_string type: string field: description: Dot-path of the offending request field. example: recipient.email type: string message: description: Human-readable issue description. type: string required: - field - code - message type: object MailboxSendScope: additionalProperties: false properties: group_public_ids: description: Delivery group public IDs (only when type=group) items: type: string type: array provider_public_ids: description: Provider public IDs (only when type=providers) items: type: string type: array type: description: >- Outbound routing strategy. `all` lets the mailbox use any team-configured provider; `providers` restricts to the listed provider IDs; `group` routes via a delivery group. enum: - all - providers - group type: string required: - type type: - object - 'null' securitySchemes: bearerAuth: bearerFormat: API Key description: >- Sendmux API key. Use a root API key for Management API routes, or a mailbox credential for Mailbox API routes. Obtain keys from the dashboard under API Keys. scheme: bearer type: http ````