How to Reduce Your Email Bounce Rate Below 1%

Your bounce rate is one of the most visible signals mailbox providers use to judge your sending reputation. A bounce rate above 2% can trigger automatic throttling; above 5% can land you on blocklists.

Hard bounces happen when an email address does not exist. Soft bounces happen when a mailbox is full or a server is temporarily unavailable. Both hurt your reputation if they happen at volume.

The fix is pre-send verification: check every address on your list — syntax, MX record, SMTP handshake, and disposable/role-based flags — before you send. OpenGuardian's bulk verification does this in minutes, not hours.