Which statement about hard bounces is true?

• A. Soft bounces are permanent.
• B. Hard bounces are permanent.
• C. Hard bounces are temporary.
• D. Soft bounces are permanent.

Answer: (B)

Hard bounces represent a permanent delivery failure for an email. They happen when the destination address is invalid or no longer exists—for example, the mailbox doesn’t exist, the domain can’t be found, or the recipient’s server rejects delivery. Because these conditions won’t resolve simply by retrying, the failure is treated as permanent. That’s why the best practice is to remove or permanently suppress hard-bounced addresses, since continuing to send to them harms sender reputation and deliverability.

Soft bounces, by contrast, are temporary delivery issues such as a full mailbox or a temporarily unavailable server, and they may be retried later. This distinction is why the statement about hard bounces being permanent is true, while the others describe soft bounces in a way that doesn’t fit their nature.