builtin_default is what a message that names no route is tried on while none of yours is the default: each channel you have, in order, each waiting 15 minutes for delivery (or for sending, where a channel can’t report delivery). When one of your routes is the default, builtin_default holds its steps.
Needs the
routes:read scope.Request
Response
200 OK
Errors
Every refusal is{"error": {"code", "message", "field"}}; field is there when one input is at fault.
Any request can also be refused for its key, its account or its rate (
key_required, invalid_key, account_suspended, plan_excludes_api, address_not_allowed, rate_limited); see the overview.