Hard Bounce in email marketing refers to an email message that is permanently undeliverable to a recipient’s email address. This occurs when the recipient’s email address is invalid, no longer in use, or has been permanently blocked by the recipient’s email service provider.
Hard bounces are a serious issue in email marketing as they can damage the sender’s reputation and lower the deliverability rate for future emails. To avoid hard bounces, it is important to regularly clean and verify email lists and monitor bounced messages.