A catch-all mailbox receives messages sent to nonexistent email addresses under the exact same domain name. For example, an email sent to the miswritten firstname.lastname@example.org will go to email@example.com if the catch-all feature has been activated for the latter. Thus, you can receive messages from buddies or customers who may have sent a message to your email address with a typographical error or to an old one, which they may still have, but you have already deleted. Just one single 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 a certain moment you may begin receiving spam emails in the catch-all mailbox and the forwarding restriction means that the spam will not be delivered to a 3rd-party mailbox.