A catch-all mailbox receives emails sent to invalid addresses under the same domain name. For instance, an email sent to the misspelled suport@domain.com will go to support@domain.com in case the catch-all feature has been enabled for the latter. In this way, you can receive email messages from pals or clients who may have sent a message to your email address with a spelling error or to an outdated one, which they may still have, but you have already deleted. Only one single mailbox per domain can be a catch-all one and email forwarding cannot be activated for such a mailbox. This is so because of the fact that at a certain point you may begin receiving spam emails in the catch-all mailbox and the forwarding limitation implies that the spam will not be delivered to a 3rd-party mailbox.