A catch-all mailbox receives messages sent to nonexistent addresses under the very same domain name. For instance, an email message sent to the miswritten suport@domain.com will be delivered to support@domain.com if the catch-all feature has been enabled for the latter. Thus, you can receive messages from partners or customers who may have sent a message to your email address with a spelling error or to an old 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 set up for such a mailbox. This is due to the fact that at a certain point you may begin receiving spam messages in the catch-all mailbox and the forwarding restriction means that the spam will not be re-sent to a 3rd-party mailbox.