Inquiries can be initiated for Global Express Guaranteed (GXG) items, Priority Mail Express International items, registered items, and insured and ordinary parcels. Inquiries are not accepted for ordinary letters, Priority Mail International Flat Rate Envelopes, Priority Mail International Small Flat Rate Priced Boxes, or M-bags. You must wait a reasonable amount of time for an international item to be delivered in the foreign country before initiating an inquiry. Time limits vary by country and may be found in IMM 921.2.