Express mailing is a special service made with an arrangement for your delivery to be expedited. In most cases your mail would be delivered within 1-3 business days by the postal service.
USA: There are two main postage types in US First class - 1 to 3 business days - First class mail is typically used for transactional mail purposes like invoices, bills and so on which requires quicker SLA and has higher sensitivity with regards to ...