Email bounce rate refers to the percentage of emails that are not successfully delivered to the intended recipient’s inbox. This can occur due to a variety of reasons, such as an invalid email address, a full inbox, or technical issues. A high email bounce rate can indicate a problem with the quality of your email list or the effectiveness of your email marketing strategy. It is an important metric for businesses to track in order to ensure the success of their email campaigns and maintain a positive reputation with email service providers.