A catch-all feature that is enabled for a given mailbox will allow you to receive emails that are sent to addresses that do not actually exist. To put it differently, if you disable an email address and somebody still sends an email to it, or to any miswritten email address under the same domain name, you’ll get the message in the catch-all mailbox. Using this feature implies that you won’t miss an email for any reason whatsoever, which could be vital in case you are running some business, for example. Since you may start receiving unsolicited messages, you can combine the catch-all functionality with email filters in order to receive only real emails in your inbox. Only one mailbox per domain name can be a catch-all one and email forwarding cannot be enabled for a catch-all mailbox.