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

    SS$_NORMAL         Normal successful completion.
    MAIL$_CODERR       Internal system error.
    MAIL$_CONITMCOD    The specified item codes perform conflicting
                       operations.
    MAIL$_ILLPERNAME   The specified personal name string is illegal.
    MAIL$_INVITMCOD    The specified item code is invalid.
    MAIL$_INVITMLEN    The specified item length is invalid.
    MAIL$_MISREQITEM   The required item is missing.
    SS$_ACCVIO         Access violation.
    Any condition values returned by $GETJPIW, LIB$FREE_VM, and
    LIB$GET_VM.