A catch-all email mailbox receives emails sent to inactive addresses under the very same domain name. 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 emails from colleagues or clients who may have sent a message to your email address with a spelling mistake or to an out-of-date one, which they may still have, but you have already deactivated. Just 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 restriction means that the spam will not be sent to a 3rd-party mailbox.