For security we can't send transfer authorization codes (aka auth or EPP codes) by email, but if you login to your account and go to your domain's dashboard, you can access the code.
Click on the unlock link to the right of Transfer Auth Code, and when the page refreshes, you will be able to copy the code.
Did you know you usually don't have to transfer a domain to use third-party web hosting? Most hosting companies can provide you with their set of nameservers or DNS records to connect domains to their service.
One of the advantages of keeping the management with a dedicated domain registrar like iwantmyname is that you can always change hosting providers without moving the domain again.