A catch-all mailbox is one that gathers all the email messages sent to nonexistent addresses. For example, if your email address is firstname.lastname@example.org, but someone miswrites it and sends a message to email@example.com, it will still be received in the catch-all mailbox that you have configured. Only one single mailbox per domain can have this feature enabled and thus you will never miss emails because the other party has an out-of-date email address or has made a spelling mistake. The disadvantage of setting up a catch-all mailbox is that you may begin receiving a lot of spam email messages, but this problem can be resolved by using anti-spam filtering software. It is also crucial to bear in mind that a mailbox with an active catch-all functionality cannot forward inbound messages to a third-party email address.