Library /sys$common/syshlp/mailhelp.hlb SELECT, Qualifiers, /REPLIED  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /REPLIED
       /NOREPLIED

    Selects messages that have been replied to with the REPLY
    command. The /NOREPLIED qualifier selects messages to which you
    have not replied.