A catch-all mailbox is one that collects all the emails sent to nonexistent email addresses. For instance, if your address is email@example.com, but somebody misspells it and sends an email to firstname.lastname@example.org, it will still be received in the catch-all mailbox that you have configured. Only one single mailbox per domain name can have this feature enabled and in this way you will never miss messages because the other side has an outdated address or has made a typographical error. The negative aspect of creating a catch-all mailbox is that you may begin receiving plenty of unsolicited bulk email messages, but this problem can be fixed by using anti-spam protection software. It’s also vital to know that a mailbox with an active catch-all functionality cannot redirect inbound email messages to a third-party email address.