A catch-all mailbox receives messages sent to nonexistent email addresses under the exact same domain name. For example, an email message sent to the mistyped suport@domain.com will be delivered to support@domain.com in case the catch-all feature has been enabled for the latter. In this way, you can get emails from buddies or customers who may have sent a message to your email address with a spelling mistake or to an outdated one, which they may still have, but you have already deleted. Only one mailbox per domain name can be a catch-all one and email forwarding cannot be enabled for such a mailbox. This is due to the fact that at some point you may start receiving spam emails in the catch-all mailbox and the forwarding limitation implies that the spam will not be re-sent to a 3rd-party mailbox.