For many channels, delivery history information is appended to the end of each message file after an unsuccessful delivery attempt has been made. With the HISTORY command, this information can be displayed. The messages to show histories for are specified by their message identification numbers shown by the most recent DIRECTORY command. That number appears in the leftmost column of the DIRECTORY command listing. Ambiguous message numbers must be qualified by the proper channel name with the /CHANNEL qualifier. Note that history information is not recorded by some channels.