A catch-all email mailbox receives email messages sent to inactive email addresses under the same domain name. For instance, a message sent to the misspelled firstname.lastname@example.org will go to email@example.com in case the catch-all feature has been activated for the latter. Thus, you can get emails from partners or clients who may have sent a message to your email address with a spelling error or to an out-of-date one, which they may still have, but you have already deleted.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 enabled for such a mailbox. The latter is due to the fact that at some point you may begin receiving spam messages in the catch-all mailbox and the forwarding restriction means that the spam will not be sent to a third-party mailbox.