A catch-all e-mailbox is one that collects all the emails sent to non-existent email addresses. For example, if your email address is firstname.lastname@example.org, but somebody mistypes it and sends an email message to email@example.com, it will still be received in the catch-all mailbox that you have set up. Just one single mailbox per domain can have this feature activated and thus you’ll never miss messages because the other party has an out-of-date address or has made a spelling error. The drawback of using a catch-all mailbox is that you may start receiving plenty of unsolicited email messages, but this issue can be solved using anti-spam protection software. It’s also important to remember that a mailbox with an activated catch-all functionality cannot redirect incoming messages to a third-party email address.