On one occasion a campaign email bounced (don't know why), but the email is valid and now I can no longer send emails to that contact.
Hi @Garry Moore
There are many reasons for an email to bounce and it indeed does not always mean that the email address itself is invalid. A Contact Person will have the status "Bounced" when there is a hard bounce (invalid address) or 5 times soft bounce (You can read more about specific bounces here). This status is meant to be not changed and it will still be bounced no matter what you change on the Contact Person. A workaround, in this case, can be creating a new Contact Person with the same email address and you can re-try sending out a Campaign to this newly created Contact Person.