A catch-all functionality that is enabled for a particular e-mailbox will allow you to receive emails that are sent to email addresses that do not actually exist. In other words, if you remove an email address and someone still sends an email message to it, or to any mistyped email address under the exact same domain, you will get 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 if you are running some company, for example. Since you may start receiving junk email messages, you can use the catch-all feature with anti-spam filtering software so as to get only legitimate emails in your inbox. Just one single mailbox per domain name can be a catch-all one and email forwarding cannot be activated for a catch-all mailbox.