A catch-all email mailbox is one that gathers all the messages sent to non-existent email addresses. For instance, if your email address is info@domain.com, but somebody miswrites it and sends an email to inof@domain.com, it will still be received in the catch-all mailbox that you have set up. Just one single mailbox per domain can have this feature enabled and in this way you will never miss emails because the other party has an out-of-date address or has made a mistake. The drawback of configuring a catch-all mailbox is that you may begin receiving lots of spam, but this issue can be solved by using anti-spam filtering software. It is also important to bear in mind that a mailbox with an active catch-all feature cannot forward incoming email messages to a 3rd-party mailbox.