Understanding email bounces is crucial for maintaining a good sending reputation. Bounces can be categorized into two primary types: hard bounces, which occur when an email address doesn't exist or has fundamental problems with the receiving mail server, and soft bounces, which happen temporarily due to issues such as mailbox fullness or DNS errors. It's essential to monitor both types of bounces to avoid negatively impacting your domain's reputation. Postmark, a popular email service provider, automatically suspends delivery for hard bounces and spam complaints, but provides tools to help users resolve issues with soft bounces. To mitigate the impact of bounces, it's recommended to engage with users, use email verification, and consider services that can help reduce the number of invalid emails entered into your application.