A catch-all mailbox is one that collects all the email messages sent to non-existent email addresses. For example, if your email address is info@domain.com, but someone misspells it and sends a message to inof@domain.com, it will still be received in the catch-all mailbox that you have set up. Only 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per domain can have this feature enabled and in this way you will never miss messages because the other side has an outdated address or has made a spelling error. The disadvantage of having a catch-all mailbox is that you may start receiving lots of unsolicited emails, but this issue can be fixed using anti-spam protection software. It is also vital to know that a mailbox with an enabled catch-all feature cannot redirect incoming messages to a 3rd-party email address.