To avoid your own accounts and hostnames becoming blocked when developing a client, the test account and test hostnames have been provided for client testing during the development process. The test account or any of the test hostnames cannot be a default within a client.
The username for the test account is simply test, and the password is also test.
The available test hostnames for Dynamic DNS are:
The available test hostnames for Dyn Standard DNS are:
Those hostnames are regularly unblocked; if one of them is blocked for update abuse, use another one.
To prevent abuse, the test account cannot be used to log into the website.