A catch-all feature that is enabled for a specific mailbox will allow you to receive email messages that are sent to email addresses that do not actually exist. Otherwise put, if you remove an email address and someone still sends an email to it, or to any miswritten email address under the exact same domain, you will receive the email in the catch-all mailbox. Using this feature means that you will no longer miss an email for any reason whatsoever, which could be essential in case you are running a business, for instance. Since you may start receiving junk messages, you can use the catch-all functionality with anti-spam filters in order to get only authentic emails in your inbox. Only one mailbox per domain name can be a catch-all one and email forwarding cannot be activated for a catch-all mailbox.