A catch-all e-mailbox is one that collects all the messages sent to nonexistent email addresses. For example, if your email address is email@example.com, but someone misspells it and sends an email to firstname.lastname@example.org, it will still be received in the catch-all mailbox that you have set up. Only one mailbox per domain can have this feature enabled and thus you’ll never miss emails because the other side has an out-of-date email address or has made a spelling mistake. The downside of using a catch-all mailbox is that you may start receiving plenty of spam emails, but this issue can be rectified using an anti-spam protection solution. It’s also crucial to remember that a mailbox with an activated catch-all functionality cannot redirect inbound email messages to a 3rd-party email address.