Email open rate is a key performance metric that indicates the percentage of recipients who open an email campaign. This metric is influenced by various factors, including subject lines, sender reputation, email personalization, and the time of sending. A high open rate suggests that an email campaign is resonating with its audience, while a low open rate may indicate issues such as unappealing subject lines, poor email deliverability, or irrelevant content. To improve open rates, businesses should experiment with A/B testing, optimize preheader text, personalize subject lines, and maintain a clean email list. Understanding open rates helps marketers assess campaign effectiveness and make data-driven decisions.