A catch-all mailbox receives email messages sent to inactive addresses under the exact same domain name. For example, a message sent to the misspelled firstname.lastname@example.org will go to email@example.com if the catch-all feature has been activated for the latter. In this way, you can receive email messages from acquaintances or customers who may have sent a message to your email address with a spelling error or to an out-of-date one, which they may still have, but you have already deleted. Just one mailbox per domain can be a catch-all one and email forwarding cannot be activated for such a mailbox. This is due to the fact that at a certain point you may start receiving spam messages in the catch-all mailbox and the forwarding limitation implies that the spam will not be redirected to a third-party mailbox.