Como faço para anexar o arquivo do diretório ao e-mail enviado com utl_smtp

FUNCTION GetFile(FolderName IN VARCHAR2, FileName IN VARCHAR2) RETURN CLOB IS

    v_bfile   BFILE; 
    v_clob    CLOB; 
    destOffset INTEGER := 1; 
    srcOffset INTEGER := 1; 
    lang_context INTEGER := DBMS_LOB.default_lang_ctx;
    warning INTEGER;

BEGIN 
    v_bfile := BFILENAME (FolderName, FileName); 
    DBMS_LOB.OPEN (v_bfile); 
    DBMS_LOB.CREATETEMPORARY(v_clob, TRUE, DBMS_LOB.SESSION);   
    DBMS_LOB.LOADCLOBFROMFILE(
        dest_lob => v_clob, 
        src_bfile => v_bfile, 
        amount => DBMS_LOB.GETLENGTH(v_bfile), 
        dest_offset => destOffset, 
        src_offset => srcOffset,
        bfile_csid => DBMS_LOB.default_csid,
        lang_context => lang_context,
        warning => warning); 

    DBMS_LOB.CLOSE(v_bfile); 

    RETURN v_clob; 

END GetFile;