Bounce Rate
The percentage of emails that fail to deliver.
Bounce rate measures the number of emails that cannot reach recipients, expressed as a percentage of the total emails sent. Bounces are classified as "hard" (permanent failures like invalid addresses) or "soft" (temporary issues like a full inbox or server downtime). A high bounce rate can harm sender reputation and deliverability, making it essential for marketers to regularly clean their email lists, validate addresses, and ensure that their campaigns comply with best practices for email marketing.