Subject lines accurately reflect content; no false urgency

CAN-SPAM §5(a)(2) prohibits subject lines that mislead recipients about the content or subject matter of the message. Prefixing promotional emails with Re: or Fwd: simulates a reply thread — a pattern FTC enforcement actions have specifically targeted. Using Action required or Your account for discount offers causes recipients to open under false pretenses, inflates spam complaints when they realize the deception, and permanently damages sender reputation scores. CASL Section 6 imposes parallel requirements for Canadian recipients: deceptive subject lines invalidate the implied consent that commercial email relies on.

Audit every subject line template and rewrite any that use deceptive framing — thread simulation, false urgency, or transactional-looking labels on promotional content.

// Subject line review — apply to every template before sending:

// WRONG
// 'Re: Following up on your last visit'   // simulates reply thread
// 'Action required: Your account'          // false urgency for a promo
// 'Only 2 hours left!'                     // scarcity claim without a real deadline

// CORRECT
// 'Your February discount — 20% off until Friday'
// 'New: Dark mode is now available'
// 'Your March invoice is ready'            // transactional — accurate

For campaign-builder tools that generate subjects dynamically, add a mandatory review checkpoint before any send exceeding 50 recipients. A one-line rule: if the subject would be accurate on a transactional email, do not use it on a promotional one.