To improve your email deliverability and open rates, it's essential to monitor your email sending reputation and address potential issues before they damage your brand. A healthy spam complaint rate is around 0.02%, but high complaint rates can indicate a problem with your emails. To reduce spam complaints, get permission through confirmed opt-in, validate emails at sign-up, and always include a low-friction way to unsubscribe. Sending relevant content to engaged users is also crucial for open rates, with the likelihood of opening decreasing after 14 emails. Aiming for an open rate of 20-30% is ideal, but this can vary depending on industry. To improve email deliverability, set up Google's Postmaster tool and consider using tools like 250ok to track signals critical to your email program. Additionally, validate emails at sign-up, clean up your email database regularly, and avoid sending irrelevant content or purchasing lists of invalid addresses. By following these tips, you can improve your email open rates, reduce spam complaints, and maintain a healthy sending reputation.