A catch-all email mailbox is one that captures all the email messages sent to invalid email addresses. For example, if your email address is email@example.com, but someone miswrites it and sends a message to firstname.lastname@example.org, it will still be received in the catch-all mailbox that you have set up. Just one mailbox per domain name can have this feature enabled and in this way you’ll never miss emails because the other party has an obsolete address or has made a typo. The downside of setting up a catch-all mailbox is that you may start receiving lots of unsolicited email messages, but this problem can be resolved by using anti-spam filtering software. It is also important to know that a mailbox with an active catch-all functionality cannot forward inbound email messages to a 3rd-party mailbox.