VMS Help MAIL Routines, MAIL$MESSAGE_GET, Condition Values Returned  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    MAIL$_MSGINFO      Informational records are successfully
                       returned.
    MAIL$_MSGTEXT      Text record is successfully returned.
    MAIL$_ILLCTXADR    The context block address is illegal.
    MAIL$_INVITMCOD    The specified item code is invalid.
    MAIL$_INVITMLEN    The specified item length is invalid.
    MAIL$_MISREQITEM   The required item is missing.
    MAIL$_NOFILEOPEN   The mail file is not open.
    MAIL$_NOMOREREC    No more records can be found.
    MAIL$_NOTREADIN    The operation is invalid; you are not reading
                       a message.
    MAIL$_RECTOBIG     The record is too large for the mail buffer.
    MAIL$_WRONGCTX     The context block is incorrect.
    MAIL$_WRONGFILE    The specified file is incorrect in this
                       context.
    SS$_ACCVIO         Access violation.
    Any condition value returned by $FIND and $UPDATE.