> ## 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. # Update a mailbox > Updates any combination of display_name, quota_bytes, and send_scope on a mailbox. The display_name and send_scope changes land in a single transaction; quota_bytes is applied afterwards because it also updates external state on our mail platform. Quota can only be set to 1073741824 (1 GB), 5368709120 (5 GB), or 53687091200 (50 GB), and cannot be shrunk below the mailbox's current usage. For optimistic concurrency, send `If-Match: ` using the ETag from a prior GET. A mismatched `If-Match` returns `409 conflict` (the server's ETag is echoed back so you can decide whether to re-fetch). Responses carry the new ETag so chained edits can pipeline without a re-GET. ## OpenAPI ````yaml /openapi-app.json patch /mailboxes/{public_id} 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}: patch: tags: - Mailboxes summary: Update a mailbox description: >- Updates any combination of display_name, quota_bytes, and send_scope on a mailbox. The display_name and send_scope changes land in a single transaction; quota_bytes is applied afterwards because it also updates external state on our mail platform. Quota can only be set to 1073741824 (1 GB), 5368709120 (5 GB), or 53687091200 (50 GB), and cannot be shrunk below the mailbox's current usage. For optimistic concurrency, send `If-Match: ` using the ETag from a prior GET. A mismatched `If-Match` returns `409 conflict` (the server's ETag is echoed back so you can decide whether to re-fetch). Responses carry the new ETag so chained edits can pipeline without a re-GET. operationId: managementUpdateMailbox parameters: - in: path name: public_id required: true schema: description: Mailbox public ID type: string - in: header name: If-Match required: false schema: description: >- Weak ETag from a prior GET. Reject with 409 conflict when the server's current ETag differs. type: string requestBody: content: application/json: schema: $ref: '#/components/schemas/UpdateMailboxBody' responses: '200': content: application/json: schema: $ref: '#/components/schemas/MailboxItemResponse' description: Updated mailbox headers: ETag: description: Weak ETag for the post-update resource. schema: type: string '400': content: application/json: schema: $ref: '#/components/schemas/ApiError' description: Invalid request body '404': content: application/json: schema: $ref: '#/components/schemas/ApiError' description: Mailbox not found '409': content: application/json: schema: $ref: '#/components/schemas/ApiError' description: '`If-Match` ETag does not match the server''s current version.' '413': content: application/json: schema: $ref: '#/components/schemas/ApiError' description: Request body too large '422': content: application/json: schema: $ref: '#/components/schemas/ApiError' description: >- Validation error — unsupported quota tier, quota below current usage, or cross-tenant send_scope reference security: - bearerAuth: [] components: schemas: UpdateMailboxBody: additionalProperties: false properties: display_name: description: Replace the display name; send null to clear it. maxLength: 254 minLength: 1 type: - string - 'null' quota_bytes: description: >- Storage quota in bytes. Allowed values: 1073741824 (1 GB), 5368709120 (5 GB), 53687091200 (50 GB). example: 5368709120 minimum: 1 type: integer send_scope: additionalProperties: false description: Replace outbound routing restrictions. properties: group_public_ids: description: >- Delivery group public IDs allowed for sending when type is `group`. items: maxLength: 128 minLength: 1 type: string type: array provider_public_ids: description: >- Provider public IDs allowed for sending when type is `providers`. items: maxLength: 128 minLength: 1 type: string type: array type: description: >- Outbound routing strategy. Use `providers` with provider_public_ids, or `group` with group_public_ids. enum: - all - providers - group type: string required: - type type: object type: object 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 ````