copy

COPY  -  copy messages into another mail file

Usage:  COPY [/type] filename [message-sequence]
  Unless specified, /type is "/mbox" and message-sequence is "current".

The COPY command copies messages to another mail file, and also leaves 
  them in the current mail file (compare to MOVE).  

If the mail file named exists, COPY adds copies of the messages to the end 
  of the file.  If the mail file does not exist, COPY creates it, unless
  the variable auto-create-files is set to NO.  If a directory is not 
  specified with the filename, COPY assumes the MAIL-DIRECTORY, which by 
  default is your home directory. 

If a type is not specified, /mbox is used for new files and the existing
  type is retained for existing files.  Use the type /mbox unless you also 
  use another mail system that needs another format.  /babyl and /mtxt 
  are the other types. 
  
Examples:
    MM>copy oldmail                #copies the current message
    MM>copy oldmail 1,3:6          #specifying messages by number
    MM>copy fred.mail from fred    #specifying messages from fred

For more help type "help" and one of these topics:
  message-sequence   get   examine   move   headers   filing
  set auto-create-files   set default-mail-type   set mail-directory