A catch-all mailbox receives emails sent to non-existent addresses under the very same domain. For instance, an email sent to the mistyped firstname.lastname@example.org will be delivered to email@example.com if the catch-all feature has been activated for the latter. In this way, you can receive email messages from friends or customers who may have sent a message to your email address with a typographical error or to an old one, which they may still have, but you have already deleted. Just one mailbox per domain name can be a catch-all one and email forwarding cannot be set up for such a mailbox. This is due to the fact that at some point you may begin receiving spam messages in the catch-all mailbox and the forwarding limitation means that the spam will not be sent to a third-party mailbox.