In UNIX, one of the intercommunication commands available to the user is mail. To use mail:


Format:
 mail -(switch) (argument)

Switches:
 
 -d   Start debugging output
 -e   Check for mail
 -F   Put the message in a file. The name of the file is
      the name of the first recipient
 -H   Print only the header information
 -I   Ignore any interrupts
 -n   Do not initialize from the mail.rc file
 -N   Do not print the header information
 -U   Convert UUCP to Internet addresses
 -v   Pass the -v flag to sendmail

 -f (filename)   Read messages from (filename) instead
                 of the mailbox.
 -f (folder)     Use file named (folder) in a directory
                 called (folder).
 -h (number)     Checks the hops made. Kills infinite
                 delivery loops.
 -r (address)    Pass the (address) argument to the
                 MTA or network delivery software.
 -s (subject)    Replace the subject header field with
                 the new (subject).
 -T (file)       Prints the article-ID of all messages
                 on (file).
 -u (username)   Allows you to read (username)'s mailbox
                 contents. You must have the proper 
                 permissions in that user's home directory.

Note: Anything in parenthesis should be replaced, such
      as (filename) to bigfile.log (note no parenthesis).

Incoming mail is stored in the system mailbox. After you open a mail message, it gets placed in the mbox in your home directory.