Final answer:
Relaying emails through a computer or network without permission is a violation of the CAN-SPAM Act and can result in additional fines.
Step-by-step explanation:
The CAN-SPAM Act sets rules for commercial email, establishes requirements for commercial messages, gives recipients the right to have you stop emailing them, and spells out tough penalties for violations. Based on the options provided, the activity that would be a violation of the CAN-SPAM Act and subject to additional fines is relay e-mails through a computer or network without permission. The other options listed, including providing an accurate e-mail address and an opt-out method, including a return e-mail address or another Internet-based response mechanism, and identifying the e-mail as an advertisement including the sender's valid physical postal address, are all requirements under the CAN-SPAM Act and would not constitute a violation.