A catch-all email mailbox receives email messages sent to non-existent email addresses under the very same domain. For instance, an email sent to the misspelled firstname.lastname@example.org will be delivered to email@example.com in case the catch-all feature has been enabled for the latter. Thus, you can receive messages from pals or customers who may have sent a message to your email address with a typographical error or to an outdated one, which they may still have, but you have already deleted. Only one mailbox per domain name can be a catch-all one and email forwarding cannot be enabled for such a mailbox. This is due to the fact that at a certain moment you may start receiving spam emails in the catch-all mailbox and the forwarding restriction means that the spam will not be sent to a 3rd-party mailbox.