Sending Outreach mailing via contact list without overriding alt email address

Content

We have a time-sensitive Outreach mailing that needs to go soon. Here’s the issue we’re running into and looking for a workaround:

1. We have a CSV file of personal email addresses for customers. These are listed as Alt Email addresses on the contact record where their primary address is their organization email. We need the mailing to go out to the email addresses on the CSV file which is why we're using a CSV file to create a contact list.
2. Once we create the contact list from the CSV file and open it, every alt email address is replaced by the customer's primary email address. This seems like a pretty stupid behavior.