A catch-all mailbox receives email messages sent to inactive addresses under the very same domain name. For example, an email message sent to the misspelled email@example.com will be delivered to firstname.lastname@example.org in case the catch-all feature has been activated for the latter. Thus, you can receive email messages from friends or customers who may have sent a message to your email address with a spelling mistake or to an outdated one, which they may still have, but you have already deleted. Just one single mailbox per domain can be a catch-all one and email forwarding cannot be set up for such a mailbox. This is due to the fact that at a certain point you may begin receiving spam email messages in the catch-all mailbox and the forwarding limitation implies that the spam will not be redirected to a third-party mailbox.