Once logged in, make sure you are in the user
panel by clicking on User Level (if you're a reseller), and then click
on the domain you want to set the default address to. If you only have
one domain on the account, you should be placed directly on a page with
a list of options. Click on "Catch-All E-Mail", and then choose what
you'd like to do. There are three options:
Fail: the user will receive a bounce email if mail is sent to the catch-all address.
Ignore: the message will just disappear. The user won't get a bounce email.
Address: the message will be sent to the email address you specify.
Once you choose one of the above three options, click on Update.