A catch-all email mailbox receives messages sent to invalid addresses under the very same domain name. For example, a 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 receive messages from pals or customers who may have sent a message to your email address with a spelling error or to an outdated one, which they may still have, but you have already disabled. Only one mailbox per domain name can be a catch-all one and email forwarding cannot be enabled for such a mailbox. The latter is due to the fact that at a certain moment 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 third-party mailbox.