A catch-all functionality that is enabled for a given mailbox will allow you to receive emails that are sent to email addresses that do not really exist. Otherwise said, if you disable an email address and somebody still sends an email message to it, or to any mistyped address under the exact same domain name, you will get the message in the catch-all mailbox. Using this feature means that you won’t miss an email for any reason whatsoever, which could be crucial if you run some business, for instance. Since you may start receiving unsolicited messages, you can use the catch-all functionality with anti-spam filtering software in order to receive only authentic messages in your inbox. Just one single mailbox per domain name can be a catch-all one and email forwarding cannot be set up for a catch-all mailbox.