A catch-all email mailbox receives email messages sent to nonexistent email addresses under the same domain name. For example, an email message sent to the misspelled firstname.lastname@example.org will be delivered to email@example.com if the catch-all feature has been enabled for the latter. Thus, you can get messages from friends or customers who may have sent a message to your email address with a spelling error or to an out-of-date one, which they may still have, but you have already deleted.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 name 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 some point you may begin receiving spam emails in the catch-all mailbox and the forwarding limitation implies that the spam will not be redirected to a third-party mailbox.