> For the complete documentation index, see [llms.txt](https://docs.mailtrap.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.mailtrap.io/developers/inbound/inboxes/create-an-inbox.md).

# Create an inbox

Create a new inbox in a folder. Requires admin access to the folder. An account can have at most 300 inboxes.

By default Mailtrap generates the inbox `address` automatically based on the `name`.

To create a catch-all inbox on your own domain, pass `domain_id` — the ID of one of the account's custom sending domains. The inbox then receives mail sent to any address on that domain, and its `address` is returned as `*@your-domain.com`. Each domain can be attached to only one inbox.

```json
{"openapi":"3.1.0","info":{"title":"Inbound","version":"2.0.0"},"tags":[{"name":"inboxes","description":"An inbox is the destination for inbound email. Each inbox is created\ninside a folder and gets a unique generated address that can receive\nmail from any sender.\n"}],"servers":[{"description":"Mailtrap API","url":"https://mailtrap.io"}],"security":[{"HeaderAuth":[]},{"BearerAuth":[]}],"components":{"securitySchemes":{"HeaderAuth":{"type":"apiKey","description":"API token in Api-Token header","in":"header","name":"Api-Token"},"BearerAuth":{"type":"http","scheme":"bearer","bearerFormat":"JWT","description":"Bearer token authentication"}},"parameters":{"folder_id":{"name":"folder_id","in":"path","required":true,"description":"Inbound folder ID","schema":{"type":"integer"}}},"schemas":{"InboxCreateInput":{"type":"object","required":["name"],"properties":{"name":{"type":"string","minLength":1,"maxLength":100,"description":"Inbox name. Must be unique within the account, across all folders."},"domain_id":{"type":"integer","description":"ID of one of the account's custom sending domains. Attaches the\ninbox to that domain, creating a catch-all inbox that receives mail\nfor any address on it. Omit to create a standard Mailtrap-hosted\ninbox. A domain can be attached to only one inbox; an unknown or\ninaccessible ID returns `422` with `domain_id: [\"does not exist\"]`.\n"}}},"Inbox":{"type":"object","required":["id","name","address","domain_id"],"properties":{"id":{"type":"integer"},"name":{"type":"string"},"address":{"type":"string","description":"The inbox's inbound address. For a standard Mailtrap-hosted inbox\nthis is a unique generated address. For a custom-domain inbox it is\nthe catch-all form `*@your-domain.com`, which receives mail sent to\nany address on that domain.\n"},"domain_id":{"type":"integer","description":"ID of the sending domain the inbox is attached to. For a\ncustom-domain inbox this is your own sending domain; for a standard\nhosted inbox it is the Mailtrap-managed domain backing the inbox.\n"}}},"ErrorResponse":{"type":"object","properties":{"error":{"type":"string"}}},"ForbiddenError":{"type":"object","properties":{"errors":{"type":"string"}}},"UnprocessableEntity":{"type":"object","properties":{"errors":{"type":"object","additionalProperties":{"type":"array","items":{"type":"string"}}}}}},"responses":{"Unauthorized":{"description":"Unauthorized","content":{"application/json":{"schema":{"$ref":"#/components/schemas/ErrorResponse"}}}},"Forbidden":{"description":"Forbidden. The token lacks the permission required for this operation\n(`Access forbidden`), has no access to the account\n(`Account access forbidden`), or Email API/SMTP is not enabled for the\norganization (empty response body).\n","content":{"application/json":{"schema":{"$ref":"#/components/schemas/ForbiddenError"}}}},"NotFound":{"description":"Not found","content":{"application/json":{"schema":{"$ref":"#/components/schemas/ErrorResponse"}}}}}},"paths":{"/api/inbound/folders/{folder_id}/inboxes":{"post":{"operationId":"createInboundInbox","summary":"Create an inbox","description":"Create a new inbox in a folder. Requires admin access to the folder.\nAn account can have at most 300 inboxes.\n\nBy default Mailtrap generates the inbox `address` automatically based\non the `name`.\n\nTo create a catch-all inbox on your own domain, pass `domain_id` — the\nID of one of the account's custom sending domains. The inbox then\nreceives mail sent to any address on that domain, and its `address` is\nreturned as `*@your-domain.com`. Each domain can be attached to only one\ninbox.\n","tags":["inboxes"],"parameters":[{"$ref":"#/components/parameters/folder_id"}],"requestBody":{"required":true,"content":{"application/json":{"schema":{"$ref":"#/components/schemas/InboxCreateInput"}}}},"responses":{"201":{"description":"Inbox created","content":{"application/json":{"schema":{"$ref":"#/components/schemas/Inbox"}}}},"401":{"$ref":"#/components/responses/Unauthorized"},"403":{"$ref":"#/components/responses/Forbidden"},"404":{"$ref":"#/components/responses/NotFound"},"422":{"description":"Validation error","content":{"application/json":{"schema":{"$ref":"#/components/schemas/UnprocessableEntity"}}}}}}}}}
```


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