Keres AI glossary · Email Deliverability

What is Email Bounce Rate?

Email bounce rate is the percentage of emails that fail to deliver and are returned. A hard bounce is a permanent failure (invalid address); a soft bounce is temporary (full mailbox, server issue). A high bounce rate signals poor list quality to mailbox providers and damages your sender reputation.

Keeping bounce rate low

Verify and clean lists before sending, remove invalid addresses, and warm new domains. High bounces from stale or purchased lists are a fast way to wreck deliverability — list hygiene is part of what Keres manages.

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Questions

Email Bounce Rate — FAQ

What’s the difference between a hard and soft bounce?

A hard bounce is a permanent delivery failure (e.g. the address doesn’t exist); a soft bounce is temporary (e.g. a full mailbox). Repeated hard bounces hurt your reputation most.

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