A catch-all mailbox is one that captures all the email messages sent to nonexistent email addresses. For instance, if your address is email@example.com, but somebody misspells it and sends an email message to firstname.lastname@example.org, it will still be received in the catch-all mailbox that you have created. Only one mailbox per domain can have this feature activated and thus you’ll never miss emails because the other party has an obsolete address or has made a spelling error. The drawback of creating a catch-all mailbox is that you may start receiving lots of unsolicited bulk emails, but this issue can be resolved by using an anti-spam protection solution. It’s also important to bear in mind that a mailbox with an enabled catch-all functionality cannot forward inbound messages to a 3rd-party address.