A "soft bounce" and a "hard bounce" are terms used to describe the delivery status of an email message.
- Soft bounce: A soft bounce occurs when an email message is temporarily undeliverable due to a temporary issue, such as a full inbox or a temporary network issue. The email server will attempt to deliver the message again at a later time.
- Hard bounce: A hard bounce occurs when an email message is permanently undeliverable due to a permanent issue, such as a non-existent email address or a blocked domain. The email server will not attempt to deliver the message again.