When editing your Newsletter Emails/Mailing List’s CSV file, you may notice that several of the CSV columns are not populated with information. For example, Name, Address1, Address2, etc.
This is because this information is not typically asked for when someone subscribes to your mailing list. By default your site only asks for email to subscribe a visitor to the mailing list.
If the shopper subscribes to your mailing list during their checkout process, then the fields are captured from their customer record, but typically (non-customer) subscribers only enter their email address on your store’s newsletter sign up form.
The additional fields are optional fields that would only work when creating a dedicated page for the newsletter to request that information. This is something that would need to be done by an HTML developer if you need to request that information for a visitor to sign up for your newsletter.