# E10008 — MaxMailboxesExceeded

Maximum number of mailboxes for this organization reached.

- **HTTP status**: `422`
- **Type**: `validation_error`
- **Name**: `MaxMailboxesExceeded`

## What to do

Delete a mailbox to free a slot, or raise the limit on a higher plan. A deleted inbox.ai address keeps its slot for 30 days (its restore window) before the slot frees; mailboxes on your own domains free their slot immediately.

## Related

- [E10xxx — Quotas](/docs/api/errors/E10xxx): every code in this range
- [Errors](/docs/api/errors): the full wire contract, status mapping, and error catalog
- [Error handling](/docs/guides/errors): branching on `type` and `code`, validation details, and `vendor_code`