Skip to main content

Bounce rates are high

Identify why messages are bouncing and clean up your audience to protect future delivery.

Symptom​

After a Broadcast, the bounce metric in your report is higher than usual — often well above a healthy range of roughly 1–2%. You may also notice slower delivery, more messages landing in spam, or a warning that sending was paused to protect your sender reputation.

Likely causes​

Bounces fall into two groups, listed here from most to least common:

  • Hard bounces — the address is invalid, misspelled, or the mailbox no longer exists. These are permanent and usually point to stale or poorly collected subscriber data.
  • Old or purchased lists — audiences that have not been mailed recently, or lists you did not build yourself, accumulate dead addresses and spam traps.
  • Soft bounces — a temporary problem such as a full mailbox, an oversized message, or a server that is briefly unavailable. Repeated soft bounces are treated like hard bounces.
  • Authentication or content flags — missing SPF/DKIM/DMARC alignment, or content that receiving servers reject, can surface as bounces.

Fixes​

  1. Read the bounce detail in your report. Open the Broadcast's report and review the bounce breakdown to see whether bounces are hard or soft (confirm the exact steps in your account).
  2. Remove hard bounces from your audience. Delete or exclude permanently failing addresses so they are not mailed again.
  3. Verify your authentication. Confirm SPF, DKIM, and DMARC are configured for your sending domain before the next Broadcast.
  4. Re-verify how you collect addresses. Use confirmed opt-in on your signup forms and stop importing purchased or scraped lists.
  5. Re-engage or retire stale subscribers. Segment out contacts you have not mailed in months and warm them slowly, or remove them.
  6. Send a smaller test Broadcast to a clean segment and confirm the bounce rate returns to a healthy range.

Still stuck?​

If bounces stay high after cleaning your audience, note the affected Edition, the sending domain, and a sample bounce message, then contact your account support team so they can review deliverability and suppression at the account level.

Canonical terms: Author, Edition, Folder (Project Folder), Broadcast. See the Glossary.