DECLARE
   lc_from_email_id   VARCHAR2 (100);
   lc_mailhost        VARCHAR2 (100)      := \'abc.com\';
   lc_connection      UTL_SMTP.connection;
   v_mail_sub         VARCHAR2 (200)      := \'Hello\';
   v_mail_body        VARCHAR2 (1000)     := \'This is the mail body\';
   v_from_email       VARCHAR2 (100)      := \'ptian@xxx.com\';
   v_to_email         VARCHAR2 (100)      := \'ptian@xxx.com\';
BEGIN
   lc_connection := UTL_SMTP.open_connection (lc_mailhost, 25);
   UTL_SMTP.helo (lc_connection, lc_mailhost);
   UTL_SMTP.mail (lc_connection, v_from_email);
   UTL_SMTP.rcpt (lc_connection, v_to_email);
   UTL_SMTP.open_data (lc_connection);
   UTL_SMTP.write_data (lc_connection, \'Subject\' || \':\' || v_mail_sub || \' \' || UTL_TCP.crlf);
   UTL_SMTP.write_data (lc_connection, UTL_TCP.crlf || v_mail_body || UTL_TCP.crlf);
   UTL_SMTP.close_data (lc_connection);
   UTL_SMTP.quit (lc_connection);
EXCEPTION
   WHEN OTHERS
   THEN
      DBMS_OUTPUT.put_line (\'Mail not sent\');
END;

ps:可以通过下边的Query来获取SMTP Server Name

select fscpv.parameter_value smtp_server_name
from   fnd_svc_comp_params_tl fscpt
,      fnd_svc_comp_param_vals fscpv
,      fnd_svc_components fsc
where  fscpt.parameter_id = fscpv.parameter_id
and    fscpv.component_id = fsc.component_id
and    fscpt.display_name = \'Outbound Server Name\'
and    fsc.component_name = \'Workflow Notification Mailer\';