A catch-all mailbox is one that gathers all the email messages sent to inactive email addresses. For instance, 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 single mailbox per domain can have this feature activated and thus you’ll never miss messages because the other party has an obsolete address or has made a spelling mistake. The negative aspect of configuring a catch-all mailbox is that you may begin receiving plenty of spam, but this issue can be fixed by using anti-spam protection software. It is also important to remember that a mailbox with an enabled catch-all feature cannot forward inbound email messages to a 3rd-party email address.