I know enough to know that I should be embarrassed to ask this question...
In SFMC I have two basic data extensions - both the result of imports from our CRM.
Data Extension 1 (DE 1) has two fields called "Contact: email" and "Record Type" Data Extension 2 (DE 2) has a single field called "email"
The destination Data Extension has two fields: "Contact: email" and "Record Type"
What I want the query to do is compare DE 1 against DE 2 and EXCLUDE any contact from DE 1 that is also on DE 2. Kind of an ad hoc suppression list.
Here is the query:
Select [Contact: Email], [Record Type] From DE 1 Where [Contact: Email] NOT IN (select Email from DE 2)
What am I doing wrong?