A catch-all email mailbox receives messages sent to inactive email addresses under the exact same domain. For example, a message sent to the mistyped email@example.com will go to firstname.lastname@example.org in case the catch-all feature has been activated for the latter. In this way, you can get email messages from colleagues or clients who may have sent a message to your email address with a typographical error or to an obsolete one, which they may still have, but you have already disabled. Just one mailbox per domain name can be a catch-all one and email forwarding cannot be activated for such a mailbox. This is due to the fact that at some moment you may begin receiving spam emails in the catch-all mailbox and the forwarding restriction implies that the spam will not be received in a third-party mailbox.