Quality Assurance: It helps in identifying grammatical errors, broken links, and other mistakes that could affect the credibility of your campaign. Objective Feedback: Getting an outsider's perspective can provide valuable insights that you might have overlooked. Optimization: Suggestions from peers can help you optimize your email design, content, and call-to-actions for better engagement. Compliance: Ensures that your emails comply with legal requirements like CAN-SPAM and GDPR.