I think it's useful, later, i will enhance it

CREATE OR REPLACE PROCEDURE send_mail (
pSender VARCHAR2,
pRecipient VARCHAR2,
pSubject VARCHAR2,
pMessage VARCHAR2) IS

mailhost CONSTANT VARCHAR2(30) := 'wzccb.com';
crlf CONSTANT VARCHAR2(2):= CHR(13) || CHR(10);
mesg VARCHAR2(1000);
mail_conn utl_smtp.connection;

BEGIN
mail_conn := utl_smtp.open_connection(mailhost, 25);

mesg := 'Date: ' ||
TO_CHAR( SYSDATE, 'dd Mon yy hh24:mi:ss') || crlf ||
'From: <'|| pSender ||'>' || crlf ||
'Subject: '|| pSubject || crlf ||
'To: '||pRecipient || crlf || '' || crlf || pMessage;

utl_smtp.helo(mail_conn, mailhost);
utl_smtp.mail(mail_conn, pSender);
utl_smtp.rcpt(mail_conn, pRecipient);
utl_smtp.data(mail_conn, mesg);
utl_smtp.quit(mail_conn);
END send_mail;
/

create or replace trigger test_sun
after servererror on database
declare
ora_server_error_msg varchar2(1000) ;
begin
ora_server_error_msg := SQLERRM(-ora_server_error(1)) ;
dbms_output.put_line(ora_server_error_msg) ;
end ;
/