A catch-all functionality that is activated for a certain mailbox will allow you to receive email messages that are sent to email addresses that do not actually exist. To put it differently, if you deactivate an email address and somebody still sends an email message to it, or to any miswritten email address under the same domain, you will receive the email in the catch-all mailbox. Using this functionality means that you won’t miss an email for any reason, which could be essential in case you run a company, for example. Since you may begin receiving spam messages, you can use the catch-all functionality with email filters so as to get only legitimate messages 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.