If a bulk email is performed with below setup under Recipients subtab:
- FIRST EMAIL ADDRESS = Transaction Email
- SECOND EMAIL ADDRESS = Customer Email
- THIRD EMAIL ADDRESS = Contact Email
and customer and transaction emails are not populated.
Based on the above scenario, the emails will be sent to the third email address selected which is the Contact Email.
But usually, there are a lot of contacts listed.
In line with this, emails will be sent to the Primary Contact selected on the Customer Record. If not available then it will be sent to the Alternate Contact.