A catch-all email mailbox is one that gathers all the emails sent to non-existent email addresses. For instance, if your address is info@domain.com, but somebody misspells it and sends an email to inof@domain.com, it will still be received in the catch-all mailbox that you have configured. Just one mailbox per domain name can have this feature enabled and thus you will never miss messages because the other party has an out-of-date address or has made a typographical error. The disadvantage of configuring a catch-all mailbox is that you may start receiving a lot of junk emails, but this issue can be rectified by using an anti-spam protection solution. It is also crucial to bear in mind that a mailbox with an active catch-all functionality cannot redirect inbound emails to a 3rd-party email address.