A catch-all email mailbox receives email messages sent to invalid addresses under the very same domain. For example, a message sent to the miswritten firstname.lastname@example.org will be delivered to email@example.com if the catch-all feature has been enabled for the latter. In this way, you can receive messages from mates or customers who may have sent a message to your email address with a spelling mistake or to an outdated one, which they may still have, but you have already disabled. Only one mailbox per domain name can be a catch-all one and email forwarding cannot be activated for such a mailbox. The latter is due to the fact that at some moment you may begin receiving spam email messages in the catch-all mailbox and the forwarding limitation implies that the spam will not be re-sent to a 3rd-party mailbox.