After the list refreshes in BBIS, there are zero email addresses in the BBIS list.
"Do Not Email Consent Solicit Code" and "Consent Solicit Code Source" are required fields to support the new GDPR consent codes for European Union solicitation and marketing. These were added in Service Pack 14 to comply with the General Data Protection Regulation (GDPR) law.
Populating these two new solicit code fields on the Web -> Manage Web Transactions -> Configure Integration screen in CRM will address this problem.
Steps to Duplicate
1) Install Service Pack 15 2) Confirm there are valid email addresses in the query that feeds the email list, and the correct Email Type is set 3) Refresh an existing email list 4) See that the list is empty.