I have Data Extension where for some reason there are two emails (Email1 data type is text, Email2 data type is EmailAddress, DE imported from salesforce report, whereas in the salesforce both the fields type is Email), I am not sure If I use this DE to send emails, which email will be used to send emails.
Case 1. If Email1 relates to Subscribers on Subscriber Key.
Case 2. If Email2 relates to Subscribers on Subscriber Key.
Also, I have seen Contact Id (salesforce id) being used for subscriber key as well.
Any help please ?