A catch-all email mailbox receives email messages sent to invalid addresses under the exact same domain. For example, an email sent to the miswritten firstname.lastname@example.org will go to email@example.com if the catch-all feature has been enabled 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 spelling mistake or to an obsolete one, which they may still have, but you have already deactivated. Just one single mailbox per domain can be a catch-all one and email forwarding cannot be enabled for such a mailbox. This is so because of the fact that at a certain moment you may begin receiving spam email messages in the catch-all mailbox and the forwarding limitation means that the spam will not be redirected to a third-party mailbox.