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Bounce and complaint types

When a Broadcast can't be delivered, or a subscriber marks it as unwanted, the platform records a reason so you can clean your audience and protect sending reputation. This page explains the common categories you'll see in reports and on subscriber records.

A hard bounce is a permanent failure — the address is invalid or the domain doesn't exist — and the subscriber is typically suppressed automatically. A soft bounce is temporary — a full mailbox or a busy server — and the platform usually retries before giving up. A complaint means a subscriber marked your message as spam through their mail provider; complaints are the strongest signal to stop mailing an address.

Reference

TypeCategoryWhat it meansTypical action
Hard bounceInvalid recipientThe mailbox does not exist or the address is malformedAddress suppressed automatically
Hard bounceNo such domainThe domain has no mail server or does not resolveAddress suppressed automatically
Soft bounceMailbox fullRecipient's inbox is over quotaRetried; suppressed after repeated failures
Soft bounceServer unavailableReceiving server is down or temporarily deferringRetried automatically
Soft bounceMessage too largeContent exceeds the recipient server's size limitReview Edition size and images
BlockPolicy / reputationReceiving server refused based on content or sender reputationInvestigate authentication and content
ComplaintSpam reportSubscriber flagged the message via their providerAddress suppressed; stop mailing
ComplaintUnsubscribe / list-unsubscribeSubscriber opted out through the mail clientHonored and suppressed

Exact labels, thresholds, and retry windows are product- and provider-specific — confirm the wording shown in your account.

Notes

  • Repeated soft bounces to the same address are usually converted to a hard bounce and suppressed after a threshold (confirm the exact threshold in your account).
  • Suppressed addresses stay excluded from future Broadcasts account-wide until you review them on the suppression list.
  • Block and complaint categories often point to authentication or content issues rather than a bad address — review sender setup before re-sending.
  • Bounce reasons come from the receiving mail server, so wording and granularity vary between providers.

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