A catch-all mailbox is one that collects all the email messages sent to invalid addresses. For example, if your address is firstname.lastname@example.org, but someone misspells it and sends a message to email@example.com, it will still be received in the catch-all mailbox that you have created. Only one single mailbox per domain can have this feature activated and in this way you will never miss emails because the other party has an out-of-date email address or has made a spelling error. The disadvantage of creating a catch-all mailbox is that you may start receiving plenty of unsolicited messages, but this problem can be solved by using anti-spam protection software. It’s also crucial to keep in mind that a mailbox with an enabled catch-all functionality cannot forward incoming email messages to a third-party address.