A catch-all email mailbox is one that collects all the messages sent to inactive addresses. For instance, if your email address is info@domain.com, but somebody misspells it and sends an email message to inof@domain.com, it will still be received in the catch-all mailbox that you have configured. Just one single mailbox per domain can have this feature enabled and in this way you will never miss messages because the other side has an out-of-date address or has made a spelling error. The drawback of setting up a catch-all mailbox is that you may begin receiving plenty of junk email messages, but this problem can be solved using an anti-spam filtering solution. It is also important to remember that a mailbox with an enabled catch-all feature cannot forward incoming emails to a third-party mailbox.