It’s advisable to designate a catch-all address only when you really need it. Spammers will quite often try to guess email addresses in your domain and when they incorrectly guess an account, that mail is then delivered to the catch-all address. This could be a problem because the volume of the incoming messages may exceed the receiving limits for your account and may result in your account being locked, and legitimate emails being delayed or blocked.
Catch-all addresses are created through the Email Aliases options. For more information on creating catch-all addresses, please see the Creating and Managing Email Aliases article.