This allows you to upload lists for use in sending targeted emails. For more information on sending emails with uploaded lists see Buz Mail > List Emails > Send/Schedule > Uploaded Recipient List in the Reference Guide.
This list is a list compiled of users, which contains their usernames from the pre-existing user database. This does not contain email addresses and you are not able to import a list of new emails to send broadcast emails to.
This is a list of members, not emails, as exported from your database. This could be a subset of your back office list, similar to that which is created using the Query Builder. For ex: you may have a list compiling in your back office which states everyone who ordered red wine. By importing that list here, you will be able to send targeted emails to that specific group. In this case, you might wish to send an email about a new red wine that is available, or a sale, etc.
The list files are usually in ".csv" file format and the list must contain the usernames of the members, as that is how Buz identifies those who should be receiving the emails.