Sender reputation is a crucial factor in determining whether emails from your domain are delivered to recipients' inboxes or marked as spam, with algorithms from email service providers (ESPs) and mailbox providers (MBPs) evaluating factors such as list quality, spam complaints, and email engagement rates. Improving sender reputation involves maintaining clean, segmented recipient lists to avoid hard and soft bounces, minimizing spam complaints by ensuring recipients have consented to receive emails, and effectively managing email frequency and content relevance. Monitoring open rates is also essential, as low engagement can negatively influence sender reputation, creating a feedback loop that impacts both delivery and open rates. Implementing and properly configuring DMARC policies is vital for authenticating emails and preventing phishing attacks, though overly strict settings can inadvertently harm sender reputation by blocking legitimate emails. By addressing common pitfalls and continuously optimizing email strategies, businesses can enhance their sender reputation, improve email deliverability, and increase engagement rates.