Hello @DawnC20 ,
Are you using a true greeting tag, or using custom fields whose labels might've been changed regarding "surname" and "firstname?" Whatever info is explicitly associated with a contact for the selected contact field (in the case of greeting tags either first name, last name, or both), then that is what will be populated. So unless your contacts' surnames were were mistakenly labelled as first names during an import, the system wouldn't be randomly sending Hello {surname} in place of the standard Hello {first name}.
When you import contacts (unique email addresses) into your dashboard, the system will retain information already associated with it, such as first name, physical address, custom field info, etc. unless new information is explicitly included under one of the contact field labels during the import process.
... View more
