Audience Exclusions: Non-identity Namespace
How do I create a segment that excludes another audience joined on a field that is not an identity namespace (in our case, email address)? The current challenge is that audience builder is all denormalized or joined on the identity namespace.
For example, I have an audience of former customers that could have the same email address as active customer accounts. If I email the former customers, I need to exclude any email address that matches an active customer.
Thank you in advance for any help.
JeffBa4