These  1) approving both changes in existing services and the establishment of new services---those are known as classification cases; 2) adjudicating complaints from anyone who believes the Postal Service is not providing rates or services as required by law; 3) issuing advisory opinions when the Postal Service proposes a substantially nationwide change in the nature of its services; and, 4) our mostly recently assigned task, providing Congress with annual reports about the costs and revenues of international mail.
Complaints from people who believe the Postal Service is not following the law should be ignored.