A catch-all mailbox is one that collects all the emails sent to invalid email addresses. For example, if your email address is firstname.lastname@example.org, but someone mistypes 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 mailbox per domain
can have this feature enabled and thus you will never miss messages because the other party has an out-of-date address or has made a spelling error.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 vital to keep in mind that a mailbox with an activated catch-all feature cannot redirect incoming messages to a 3rd-party mailbox.