Use the guest tab to view a list of guests to your business.  Filter by date,  by agreement to join your mailing list,  or any of the flags you've used in the past.  Flags can be added to guests from this screen by clicking set flags,  ticking the relevant boxes and finally saving the changes.

Clicking Download Data will download a file with contact details for your guests.  Download Emails will download only their email addresses and names.  The data in the files is affected by the filters used on this page.  Please note the Emails file won't flag which guests have agreed to join your mailing list.