If you want to use an email address linting service or manually manage your recipients, you can download your Sendloop subscriber lists.
After logging in to your Sendloop account, navigate to the Subscriber Management page using the Subscribers link on the navigation bar.
You will see individual boxes, each of which represents a subscription list. Choose the one in which you're interested, and click Options on the lower right of the box. This brings up a drop-down menu where you can select Download subscribers.
Sendloop will then export your subscriber list into a .txt file. Your browser will download this file immediately, and when complete, you can navigate to your browser's download folder for your file.