A catch-all functionality that is activated for a specific mailbox will allow you to receive emails that are sent to email addresses that do not really exist. To state it differently, if you disable an email address and someone still sends a message to it, or to any misspelled address under the same domain, you will get the message in the catch-all mailbox. Using this functionality implies that you won’t miss an email for any reason, which could be essential in case you run a business, for example. Since you may start receiving unsolicited messages, you can use the catch-all option with email filters in order to receive only authentic messages in your inbox. Just one mailbox per domain can be a catch-all one and email forwarding cannot be enabled for a catch-all mailbox.