Hard bounce
The address does not exist or the domain rejects it permanently. The lead is suppressed and will not be contacted again.
Soft bounce
A temporary condition — mailbox full, server unavailable, greylisting. Delivery may be retried.
Why the distinction matters
Hard bounces are what damage reputation. A run of soft bounces to one domain usually means that receiver is throttling you — slow down rather than push harder.
Important notes
Repeated soft bounces to the same address eventually behave like a hard bounce. Do not keep a persistently failing address in rotation.
Was this article helpful?