A catch-all email mailbox receives emails sent to non-existent email addresses under the same domain. For instance, a message sent to the mistyped firstname.lastname@example.org will be delivered to email@example.com if the catch-all feature has been enabled for the latter. In this way, you can get email messages from acquaintances or clients who may have sent a message to your email address with a spelling mistake or to an outdated one, which they may still have, but you have already deactivated.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 activated for such a mailbox. This is due to the fact that at a certain moment you may start receiving spam emails in the catch-all mailbox and the forwarding limitation means that the spam will not be re-sent to a 3rd-party mailbox.