This webinar emphasizes the critical role of "list health" in achieving successful email inbox delivery. List health is defined as the overall quality of an email list, reflecting subscriber engagement, activity, and cleanliness, including valid email addresses and willing recipients. Maintaining a healthy list is paramount as it directly affects inbox placement rates and sender reputation. Sender reputation, a score assigned by mailbox providers like Gmail and Yahoo, is heavily influenced by list health and determines email deliverability. Key metrics for measuring list health include bounce rate, complaint rate, unsubscribe rate, and engagement rate. Bounce rate, ideally below 2%, indicates undelivered emails and should be minimized by cleaning lists of invalid addresses. Complaint rate, ideally under 0.1%, reflects spam reports and necessitates sending only to opted-in subscribers and simplifying unsubscribing. Unsubscribe rate, while natural, should be monitored and kept below 0.5% by providing relevant and valuable content. Engagement rate, ideally above 15%, measures opens and clicks, signaling subscriber interest and positively impacting sender reputation. Best practices for maintaining a healthy list include employing double opt-in to ensure subscriber willingness, regularly cleaning lists to remove inactive or invalid emails, segmenting lists for targeted content, personalizing emails, consistently delivering valuable content, and ensuring easy unsubscription. Regularly monitoring list health metrics allows for proactive adjustments and sustained inbox delivery success. In conclusion, prioritizing list health through these strategies is essential for effective email marketing, safeguarding sender reputation, and reliably reaching subscribers' inboxes.