A catch-all mailbox is one that gathers all the messages sent to inactive email addresses. For instance, if your email address is email@example.com, but someone miswrites it and sends an email message to firstname.lastname@example.org, it will still be received in the catch-all mailbox that you have configured. Only one mailbox per domain can have this feature activated and in this way you will never miss emails because the other side has an outdated email address or has made a spelling error. The downside of configuring a catch-all mailbox is that you may begin receiving a lot of unsolicited bulk messages, but this problem can be rectified by using an anti-spam protection solution. It’s also crucial to know that a mailbox with an enabled catch-all functionality cannot redirect incoming email messages to a third-party mailbox.