Spoilers: it's simple.
Before you can start receiving emails, you'll need a veil. A veil is similar to an email address in many ways, but with some key differences:
You can generate as many veils as you need.
You can use your veil where you would normally use your own email address. Do keep in mind that a veil's inbox is publicly accessible. While it's highly improbable anyone will receive the same veil as you, it's not mathematically impossible.
We strongly recommend you DO NOT use a veil for anything where you expect to receive sensitive information. We can't help you if you do. Seriously.
Once you have the link to your veil's inbox, you'll be able to see the emails come in:
You can use your veil as a single use, and grab a new one next time you need it, or you can bookmark it. Bookmarking gives you the option of re-using the same veil in the future. Keep in mind that a veil's inbox is ephemeral, and all received messages will inevitably disappear.
All veils and their messages are ephemeral, and very short lived. Once access to a veil is lost, it can never be recovered unless you find the original link. There is no point in contacting staff about lost veils or messages; we can't help you.
Do keep in mind that inbox URLs are publicly visible. Anyone with the link can view the inbox. Treat it carefully.