You can download your invoices by clicking on "Billing" in your Wild Mail dashboard.
1. Open your Wild Mail account, scroll down the main navigation menu and go the Billing section. The link to your billing section is only available from the main dashboard. Click on the W logo if you can't see it.
2. Once you're on the billing page, click on "Billing Information" and scroll down. You will see all your past invoices and can download them.