Lodgee the dump is meant as a way to import your forum elsewhere, e. g.: your own hosting. You need to import it into a MySQL database. Only then you can query it (or open it in something like phpMyAdmin or Adminer).
Since all data is in the raw text dump that you have downloaded, it is also possible to extract what you need from the file itself, with a bit of an effort. As far as I know, the E-mails shouldn't be scattered, and there should be a section to populate the users table somewhere in the file.
You can also send me an E-mail to me@kevo.link with your forum name/URL and I'll extract the addresses for you. That seems like the best option for you
