A catch-all mailbox receives email messages sent to inactive email addresses under the very same domain. For instance, a message sent to the miswritten suport@domain.com will go to support@domain.com if the catch-all feature has been activated for the latter. In this way, you can get emails from colleagues or clients who may have sent a message to your email address with a typo or to an old 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 a certain moment you may begin receiving spam email messages in the catch-all mailbox and the forwarding limitation implies that the spam will not be received in a third-party mailbox.