A catch-all mailbox is one that gathers all the email messages sent to invalid email addresses. For example, if your address is email@example.com, but somebody 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per domain name can have this feature enabled and thus you will never miss messages because the other party has an out-of-date address or has made a spelling error. The negative aspect of using a catch-all mailbox is that you may begin receiving plenty of junk messages, but this issue can be rectified using an anti-spam filtering solution. It’s also essential to know that a mailbox with an enabled catch-all functionality cannot forward inbound emails to a third-party mailbox.