A catch-all mailbox is one that collects all the emails 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 configured. Just one mailbox per domain can have this feature activated and thus you’ll never miss messages because the other party has an outdated email address or has made a spelling mistake. The disadvantage of using a catch-all mailbox is that you may start receiving lots of spam emails, but this issue can be resolved by using an anti-spam protection solution. It is also essential to remember that a mailbox with an enabled catch-all functionality cannot forward inbound messages to a third-party mailbox.