Direct answer
Verification is a snapshot, not a delivery guarantee. A mailbox may close, a catch-all server may reject later, or delivery may fail because of sender reputation, authentication or policy blocks.
More questions and answers
What do I do after a hard bounce?
Stop sending to the address, retain it in the suppression list, and correct or revalidate it only if you have a good reason and current permission. Do not repeatedly retry an unchanged hard-bounced address.
Should I delete emails after one soft bounce?
Not immediately. A soft bounce can indicate a full mailbox, temporary outage or rate limit. Follow the sending platform's retry and suppression rules.
What does 550 user unknown mean in an email bounce?
It usually indicates the recipient mailbox was not accepted, although codes and server wording matter. Suppress the address and inspect the complete bounce response before making a final classification.
Does a 554 bounce mean the email address is fake?
Not necessarily. A 554 response can be a policy or spam-related refusal. Check the server text, sending authentication and reputation before classifying the recipient address as invalid.
Why do my emails bounce only after I upload an old list?
Addresses can expire as people leave jobs or change providers, and a historic suppression list may be missing. Reconfirm permission, merge prior bounces and verify before sending.
Can I remove bounced contacts without losing their records?
Yes. Mark them as non-sendable or suppress them instead of deleting the full CRM history. Keep the original reason and date for future imports.
Why are all emails at one company bouncing?
The domain may have changed mail providers, lost MX records, or begun rejecting your sender. Check domain-level failures and your sender configuration before deleting every contact.
What bounce rate should I aim for after cleaning?
Aim to minimise hard bounces, but there is no universal zero-bounce promise. Monitor your provider's limits and Google's sender guidance as well as complaints, authentication and list permission.