A catch-all email mailbox receives email messages sent to invalid email addresses under the same domain. For instance, an email message sent to the miswritten firstname.lastname@example.org will go to email@example.com in case the catch-all feature has been enabled for the latter. In this way, you can get emails from mates or clients who may have sent a message to your email address with a spelling mistake or to an outdated one, which they may still have, but you have already deleted.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 a certain moment you may begin receiving spam emails in the catch-all mailbox and the forwarding limitation implies that the spam will not be sent to a 3rd-party mailbox.