 In 2016, the USPS had its fifth straight annual operating loss, in the amount of $5.59 billion, of which $5.8 billion was the accrual of unpaid mandatory retiree health payments.First-class mail volume peaked in 2001, declining by 43% as of 2017 due to the increasing use of email and the World Wide Web for correspondence and business transactions.Private courier services, such as FedEx and United Parcel Service (UPS), directly compete with USPS for the delivery of urgent letters and packages.