Buy mailboxes - InboxKit

Purchase and provision mailboxes on domains that are already added to your workspace.

After a successful request, each mailbox is created in a "scheduled" status and is automatically provisioned in the background, typically within a few minutes. You can use the Check Mailbox Status endpoint to track provisioning progress.

Payment:

By default, mailboxes are allocated from your subscription's available mailbox slots (use_wallet_balance is false).

Set use_wallet_balance to true to pay using your team's wallet credit balance instead.

Azure mailboxes always use wallet credits, regardless of the use_wallet_balance setting.

Set warmup_addon_enabled to true to add warmup to every mailbox in the request. The first month of warmup is charged to your wallet credit balance together with this purchase, even when the mailboxes use your subscription slots. Your wallet must cover the whole purchase, otherwise the request fails and nothing is created. Warmup is available for GOOGLE, MICROSOFT and AZURE mailboxes.

Prerequisites:

The domain must already exist in your workspace (added via the Domain Management API).

If the domain has had its admin mailbox cancelled and has no active admin, new mailboxes cannot be added to that domain.

Rules:

All mailboxes on a given domain must use the same platform. You cannot mix platforms (e.g., GOOGLE and MICROSOFT) on one domain.

Maximum 5 mailboxes per domain for GOOGLE and MICROSOFT. Maximum 100 per domain for AZURE.

Usernames are automatically converted to lowercase.

If the same username and domain combination appears more than once in the request, only the first occurrence is used.

Provide your bearer token in the

Authorization

header when making requests to protected resources.

Example:

Authorization: Bearer ********************

Responses

🟢200OK

application/json

Mailboxes have been scheduled for provisioning. Each mailbox starts with a status of 'scheduled'. Use the Check Mailbox Status endpoint to track provisioning progress.

Bodyapplication/json

🟠400Bad Request

🟠401Unauthorized

🟠402Payment Required

🟠404Not Found

🔴500Server Error

curl --location 'https://api.inboxkit.com/v1/api/mailboxes/buy' \ --header 'X-Workspace-Id;' \ --header 'Authorization: Bearer <token>' \ --header 'Content-Type: application/json' \ --data '{ "mailboxes": [ { "first_name": "John", "last_name": "Doe", "username": "john.doe", "platform": "GOOGLE", "domain_name": "example.com" } ] }'

{ "error": false, "message": "Mailbox scheduled to be assigned to domains successfully", "mailboxes": [ { "uid": "a1b2c3d4-e5f6-7890-abcd-ef1234567890", "domain_name": "example.com", "first_name": "John", "last_name": "Doe", "username": "john.doe", "platform": "GOOGLE", "status": "scheduled", "renewal_date": null, "renewal_cycle": "monthly", "createdAt": "2026-01-15T10:30:00.000Z", "updatedAt": "2026-01-15T10:30:00.000Z" } ] }