Bounce (hard and soft)
Also called: Hard bounce, Soft bounce, NDR, DSN
A bounce is an email that couldn’t be delivered. A hard bounce is permanent (the address or domain doesn’t exist); a soft bounce is temporary (a full mailbox, a busy server, a message too large).
How it affects cold email
Hard bounces are a strong sign that a list wasn’t built from real, current addresses, so they damage reputation quickly. Never email a hard-bounced address again. Soft bounces can be retried a few times before giving up.
Some bounces arrive straight away from the receiving server; others arrive later as a bounce report (delivery status notification) in your inbox.
How Inboxed handles it
- Hard bounces, whether returned by the server at send time or found later in a bounce report in your mailbox, stop the lead’s sequence and add the address to the suppression list.
- Temporary failures are retried 30 minutes later, up to 3 attempts, then the lead is taken out of the campaign. Emails that never send are never charged.
Related terms
Sources
Sources checked on 8 November 2026. Rules change, so check the source before you rely on a detail.
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