A catch-all email mailbox is one that collects all the messages sent to invalid addresses. For instance, if your email address is email@example.com, but someone miswrites 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 single mailbox per domain can have this feature activated and in this way you will never miss messages because the other side has an outdated address or has made a typographical error. The drawback of using a catch-all mailbox is that you may begin receiving plenty of unsolicited bulk emails, but this problem can be resolved by using an anti-spam filtering solution. It is also vital to know that a mailbox with an enabled catch-all feature cannot forward incoming emails to a 3rd-party mailbox.