A catch-all email mailbox is one that collects all the messages sent to non-existent addresses. For example, if your email address is firstname.lastname@example.org, but someone misspells it and sends an email message to email@example.com, it will still be received in the catch-all mailbox that you have created. Just one mailbox per domain can have this feature activated and in this way you will never miss emails because the other party has an outdated address or has made a typographical error. The drawback of having a catch-all mailbox is that you may begin receiving lots of junk email messages, but this problem can be rectified using anti-spam filtering software. It is also important to remember that a mailbox with an active catch-all functionality cannot redirect incoming email messages to a third-party mailbox.