If a contact has bounced, it is completely and permanently blocked.
This means that the contact can never be written to again. A final block will be applied if, for example:
- the email address is wrong - either because there is a typo in the email address, or because the recipient has deleted this email address
- there is something wrong with the domain (the one behind the @) - again, a typo may be the cause of this.
- the email has been rejected due to suspected spam.
- the sender domain is rejected because of a bad reputation.
If you were to write to contacts who are already blocked, this would give you a negative reputation. The emails are much more likely to be rejected as spam and no longer arrive in your recipients' inboxes - a situation that should be avoided.