A catch-all email mailbox is one that captures all the email messages sent to non-existent addresses. For example, if your email 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 configured. Just one single mailbox per domain can have this feature enabled and thus you’ll never miss emails because the other side has an out-of-date address or has made a spelling mistake. The negative aspect of configuring a catch-all mailbox is that you may begin receiving plenty of spam messages, but this issue can be fixed using anti-spam protection software. It’s also crucial to remember that a mailbox with an enabled catch-all functionality cannot redirect incoming email messages to a third-party email address.