A catch-all functionality that is enabled for a certain email mailbox will allow you to receive emails that are sent to email addresses that do not really exist. In other words, if you remove an email address and someone still sends an email message to it, or to any misspelled email address under the exact same domain, you’ll receive the message in the catch-all mailbox. Using this functionality implies that you will no longer miss an email for any reason, which could be vital in case you are running some company, for example. Since you may start receiving spam messages, you can use the catch-all option with email filters in order to receive only legitimate email messages in your inbox. Just one mailbox per domain can be a catch-all one and email forwarding cannot be activated for a catch-all mailbox.