Envío de Mail desde PL/SQL

CREATE OR REPLACE PROCEDURE EnviarCorreo(ENVIA IN VARCHAR2,
RECIBE IN VARCHAR2,
ASUNTO IN VARCHAR2,
MENSAJE IN VARCHAR2)
IS
mailhost VARCHAR2(30) := ‘SERVIDORSMTP’;
mail_conn utl_smtp.connection;
crlf VARCHAR2( 2 ):= CHR( 13 ) || CHR( 10 );
mesg VARCHAR2( 32767 );
BEGIN
mail_conn := utl_smtp.open_connection(mailhost, 25);
mesg:=-- 'Date: ' || TO_CHAR( SYSDATE, 'yyyy mm  dd  hh24:mi:ss' ) || crlf ||
'From: <'||ENVIA||'>' || crlf ||
'Subject: '||ASUNTO || crlf ||
'To: '||RECIBE || crlf ||
'' || crlf || MENSAJE;
utl_smtp.helo(mail_conn, mailhost);
utl_smtp.mail(mail_conn, ENVIA);
utl_smtp.rcpt(mail_conn, RECIBE);
utl_smtp.data(mail_conn, mesg);
utl_smtp.quit(mail_conn);
END;