post https://emailapi.netcorecloud.net/v6/subaccounts
Creates a subaccount under your master account. Subaccounts function like regular Email API accounts but are credit-controlled by the master account. By default, subaccounts have "unlimited" credit access from the master. To restrict usage, set credit_type to one_time_credit and allocate credits manually or on a recurring schedule. A confirmation email is sent to the provided address. If no password is set, the confirmation link also serves as a password setup link.