Bounce (email)
What is Bounce (email)?
An email bounce is a delivery failure reported back to the sender — a hard bounce means the address is permanently invalid (doesn't exist, domain doesn't resolve), while a soft bounce means a temporary issue (mailbox full, server briefly unavailable) that may succeed on a later retry. Sending platforms track bounce rate closely and automatically suppress repeat hard-bounce addresses from future sends, since a high bounce rate directly damages a sender's reputation with mailbox providers.
More detail
A hard bounce should generally be suppressed from future sends immediately, since retrying delivery to a permanently invalid address only continues to hurt sender reputation with no chance of success.
A soft bounce is commonly retried a limited number of times before being treated as a hard bounce if the underlying issue never resolves, since an indefinitely retried address is still a deliverability risk.
Frequently asked
- What's the difference between a hard bounce and a soft bounce?
- A hard bounce indicates a permanent failure — the address doesn't exist or the domain is invalid — and should be suppressed from future sends; a soft bounce indicates a temporary issue, like a full mailbox, that may succeed if retried later.
- Why does a high bounce rate hurt future email deliverability?
- Mailbox providers use bounce rate as a signal of sender quality — a sender that repeatedly emails invalid addresses looks like it has poor list hygiene or is potentially spamming, which can push even legitimate future messages into spam folders.
See also
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