A catch-all email mailbox receives messages sent to nonexistent addresses under the very same domain. For example, a message sent to the misspelled email@example.com will go to firstname.lastname@example.org in case the catch-all feature has been activated for the latter. Thus, you can get email messages from pals or clients who may have sent a message to your email address with a typographical error or to an out-of-date one, which they may still have, but you have already deleted. Only one single mailbox per domain name can be a catch-all one and email forwarding cannot be set up for such a mailbox. This is so because of the fact that at a certain point you may start receiving spam emails in the catch-all mailbox and the forwarding restriction means that the spam will not be re-sent to a third-party mailbox.