A catch-all email mailbox receives messages sent to invalid email addresses under the exact same domain name. For example, a message sent to the misspelled email@example.com will go to firstname.lastname@example.org in case the catch-all feature has been enabled for the latter. Thus, you can receive messages from buddies or clients who may have sent a message to your email address with a typo or to an obsolete 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 a certain point you may begin receiving spam email messages in the catch-all mailbox and the forwarding limitation implies that the spam will not be sent to a 3rd-party mailbox.