A catch-all mailbox is one that gathers all the messages sent to invalid addresses. For example, if your email address is email@example.com, but somebody mistypes it and sends an email to firstname.lastname@example.org, it will still be received in the catch-all mailbox that you have created. Only one mailbox per domain name can have this feature enabled and thus you’ll never miss messages because the other party has an outdated address or has made a spelling error. The negative aspect of creating a catch-all mailbox is that you may begin receiving plenty of spam email messages, but this problem can be resolved by using anti-spam protection software. It is also vital to bear in mind that a mailbox with an active catch-all functionality cannot forward incoming email messages to a 3rd-party email address.