A catch-all mailbox is one that gathers all the emails sent to inactive addresses. For example, if your address is email@example.com, but somebody miswrites it and sends an email message to firstname.lastname@example.org, it will still be received in the catch-all mailbox that you have configured. 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 email address or has made a mistake. The disadvantage of creating a catch-all mailbox is that you may start receiving a lot of unsolicited emails, but this problem can be rectified by using an anti-spam protection solution. It is also crucial to remember that a mailbox with an enabled catch-all feature cannot redirect inbound emails to a third-party address.