A catch-all email mailbox receives messages sent to non-existent email addresses under the exact same domain. For example, an email message sent to the misspelled email@example.com will be delivered to firstname.lastname@example.org if the catch-all feature has been activated 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get emails from buddies or clients who may have sent a message to your email address with a spelling mistake or to an outdated one, which they may still have, but you have already deactivated. Just one mailbox per domain 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 start receiving spam emails in the catch-all mailbox and the forwarding limitation means that the spam will not be delivered to a third-party mailbox.