A catch-all mailbox receives email messages sent to nonexistent email addresses under the very same domain name. For instance, a message sent to the miswritten email@example.com will be delivered to firstname.lastname@example.org in case the catch-all feature has been enabled for the latter. Thus, you can get email messages from buddies or customers who may have sent a message to your email address with a spelling mistake or to an obsolete 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 activated for such a mailbox. This is due to the fact that at some moment you may start receiving spam messages in the catch-all mailbox and the forwarding limitation implies that the spam will not be delivered to a 3rd-party mailbox.