A catch-all mailbox receives emails sent to non-existent email addresses under the very same domain. For instance, 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 get email messages from partners or customers who may have sent a message to your email address with a typographical error or to an out-of-date one, which they may still have, but you have already disabled. Just one 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 some point you may begin receiving spam email messages in the catch-all mailbox and the forwarding limitation implies that the spam will not be re-sent to a 3rd-party mailbox.