On Windows work group machines (that is machines that are not associated with a domain) it is necessary to show identity in another way to be able to print via print.uni.au.dk.
You need to make an additions in Credential Manager.
How to:
Open Control Panel.
If it is on ’View by: Category’ change it to ’View by: Small icons’.
Double click on Credential Manager.
Choose ’Add a Windows credential’.
Write 'print.uni.au.dk' followed by username and password – It will in most cases match those uesed on webmail (mail.au.dk). Remember to put the domain in front of the username. Fx UNI\AUxxxxxx and the password from "Mit.au.dk"