The Federal Trade Commission brings an enforcement action against an unsolicited commercial email vendor (spammer) for violating the provisions of the Federal Trade Commission Act that prohibit "unfair or deceptive acts or practices in commerce."

After formal adjudication under sections 554-557 of the APA, the Commission adopts an order and issues a rule providing:

1. failure to provide an operative return address on a spam message is (a) deceptive and (b) unfair; and
2. sending more than 100 identical messages without permission of any email service through which the messages are sent is unfair.

What procedural challenges can be made to these decisions?