A catch-all email mailbox is one that collects all the email messages sent to non-existent email addresses. For instance, if your address is email@example.com, but someone mistypes it and sends an email message to firstname.lastname@example.org, it will still be received in the catch-all mailbox that you have configured. Only one mailbox per domain can have this feature activated and in this way you will never miss messages because the other side has an obsolete address or has made a typo. The drawback of having a catch-all mailbox is that you may begin receiving a lot of junk emails, but this problem can be solved using anti-spam filtering software. It is also crucial to remember that a mailbox with an active catch-all functionality cannot redirect inbound emails to a third-party email address.