Monitoring email delivery and reputation is crucial for businesses, as it can be affected by various factors such as IP reputation, domain reputation, and configuration mistakes. While email service providers (ESPs) can monitor delivery to some extent, they may not be able to diagnose all issues. Fortunately, there are several tools and techniques available to help track and measure delivery rates, diagnose potential problems, and ensure timely delivery. These include monitoring DNS records, IP address blacklists, and IP/domain reputation, as well as tracking real delivery times with MailHandler, a tool that can send emails and retrieve details on delivery speed. By regularly reviewing and monitoring these factors, businesses can identify and fix issues before they impact customer inboxes.