A catch-all mailbox receives emails sent to nonexistent addresses under the same domain name. For instance, a message sent to the misspelled suport@domain.com will go to support@domain.com in case the catch-all feature has been enabled for the latter. In this way, you can get emails from buddies or clients who may have sent a message to your email address with a spelling mistake or to an outdated one, which they may still have, but you have already deleted. Just one single mailbox per domain name can be a catch-all one and email forwarding cannot be set up for such a mailbox. This is so because of the fact that at some moment you may begin receiving spam emails in the catch-all mailbox and the forwarding limitation means that the spam will not be redirected to a third-party mailbox.