A catch-all mailbox receives messages sent to inactive addresses under the same domain name. For instance, a message sent to the misspelled firstname.lastname@example.org will be delivered to email@example.com if the catch-all feature has been activated for the latter. In this way, you can receive email messages from pals or customers who may have sent a message to your email address with a spelling error or to an out-of-date one, which they may still have, but you have already disabled. Only one single mailbox per domain can be a catch-all one and email forwarding cannot be set up for such a mailbox. The latter is due to the fact that at a certain moment you may start receiving spam messages in the catch-all mailbox and the forwarding restriction means that the spam will not be redirected to a 3rd-party mailbox.