A catch-all mailbox is one that collects all the messages sent to inactive addresses. For instance, if your address is [email protected], but somebody mistypes it and sends an email message to i[email protected], it will still be received in the catch-all mailbox that you have set up. Just one single mailbox per domain name can have this feature enabled and thus you will never miss emails because the other side has an out-of-date address or has made a spelling mistake. The negative aspect of using a catch-all mailbox is that you may begin receiving a lot of unsolicited emails, but this issue can be resolved by using an anti-spam filtering solution. It is also essential to bear in mind that a mailbox with an activated catch-all functionality cannot forward incoming email messages to a 3rd-party email address.