A catch-all email mailbox is one that captures all the email messages sent to nonexistent email addresses. For instance, if your email address is email@example.com, but someone miswrites it and sends a message to firstname.lastname@example.org, it will still be received in the catch-all mailbox that you have created. Just one mailbox per domain can have this feature activated and thus you will never miss messages because the other side has an outdated email address or has made a typographical error. The disadvantage of configuring a catch-all mailbox is that you may begin receiving a lot of spam emails, but this issue can be resolved using an anti-spam protection solution. It is also important to bear in mind that a mailbox with an activated catch-all feature cannot forward inbound emails to a 3rd-party email address.