Email bounce rate measures the percentage of emails that were not successfully delivered to recipients. Bounces are categorized into two types: soft bounces, which occur due to temporary issues such as a full inbox, and hard bounces, which happen when an email address is invalid or no longer in use. A high email bounce rate can negatively impact sender reputation and email deliverability, potentially causing future emails to be flagged as spam. To reduce bounce rates, businesses should regularly clean their email lists, verify addresses before sending campaigns, and use proper email authentication methods such as SPF, DKIM, and DMARC. Understanding bounce rates helps organizations improve email list quality, maintain high engagement levels, and ensure their messages reach the intended audience.