Blocking Outlook Calendar through PLSQL Code

-- Following code can be used for blocking the calendar of the recipients through email 
-- sent using PLSQL Code.
-- Create the following function

CREATE OR REPLACE FUNCTION ical_event (
   p_summary         IN VARCHAR2
 , p_organizer_name  IN VARCHAR2
 , p_organizer_email IN VARCHAR2
 , p_start_date      IN DATE
 , p_end_date        IN DATE
 , p_version         IN VARCHAR2 := NULL
 , p_prodid          IN VARCHAR2 := NULL
 , p_calscale        IN VARCHAR2 := NULL
 , p_method          IN VARCHAR2 := NULL
)
   RETURN VARCHAR2 

AS  

   l_retval VARCHAR2(32767);
   l_lf     CHAR(1) := CHR(10);

BEGIN

   l_retval := ''
      || 'BEGIN:VCALENDAR' || l_lf
      || 'VERSION:' || NVL(p_version,'2.0') || l_lf
      || 'PRODID:' || NVL(p_prodid,'-//Your company name//NONSGML ICAL_EVENT//EN') || l_lf
      || 'CALSCALE:' || NVL(p_calscale,'GREGORIAN') || l_lf
      || 'METHOD:' || NVL(p_method,'REQUEST') || l_lf
      || 'BEGIN:VEVENT' || l_lf
      || 'SUMMARY:' || p_summary || l_lf
      || 'ORGANIZER;CN="' || p_organizer_name || '":MAILTO:' || p_organizer_email || l_lf
      || 'DTSTART:' || TO_CHAR(p_start_date,'YYYYMMDD') || 'T' || TO_CHAR(p_start_date,'HH24MISS') || l_lf
      || 'DTEND:' || TO_CHAR(p_end_date,'YYYYMMDD') || 'T' || TO_CHAR(p_end_date,'HH24MISS') || l_lf
      || 'DTSTAMP:' || TO_CHAR(SYSDATE,'YYYYMMDD') || 'T' || TO_CHAR(SYSDATE,'HH24MISS') || l_lf
      || 'UID:' || RAWTOHEX(SYS_GUID()) || '@yoururl.com' || l_lf
      || 'STATUS:NEEDS-ACTION' ||  l_lf
      || 'END:VEVENT' || l_lf
      || 'END:VCALENDAR';
   
   RETURN l_retval;
      
END ical_event;


--Create the following procedure (replace "yoururl" as needed): 

CREATE OR REPLACE PROCEDURE send_ical_email (
   p_from      IN VARCHAR2
 , p_to        IN VARCHAR2
 , p_subj      IN VARCHAR2
 , p_body_html IN VARCHAR2
 , p_body_ical IN VARCHAR2
)

AS

   l_connection UTL_SMTP.CONNECTION;
   l_mail_serv  VARCHAR2(50) := 'mail.yoururl.com';
   l_mail_port  PLS_INTEGER := '25';
   l_lf         CHAR(1) := CHR(10);
   l_msg_body   VARCHAR2(32767);

BEGIN
   
   l_msg_body :=
         'Content-class: urn:content-classes:calendarmessage' || l_lf
      || 'MIME-Version: 1.0' || l_lf
      || 'Content-Type: multipart/alternative;' || l_lf
      || ' boundary="----_=_NextPart"' || l_lf
      || 'Subject: ' || p_subj || l_lf 
      || 'Date: ' || TO_CHAR(SYSDATE,'DAY, DD-MON-RR HH24:MI') || l_lf
      || 'From: <' || p_from || '> ' || l_lf 
      || 'To: ' || p_to || l_lf 
      || '------_=_NextPart' || l_lf
      || 'Content-Type: text/plain;' || l_lf
      || ' charset="iso-8859-1"' || l_lf
      || 'Content-Transfer-Encoding: quoted-printable' || l_lf
      || l_lf
      || 'You must have an HTML enabled client to view this message.' || l_lf
      || l_lf
      || '------_=_NextPart' || l_lf
      || 'Content-Type: text/html;' || l_lf
      || ' charset="iso-8859-1"' || l_lf
      || 'Content-Transfer-Encoding: quoted-printable' || l_lf
      || l_lf
      || p_body_html || l_lf
      || l_lf
      || '------_=_NextPart' || l_lf
      || 'Content-class: urn:content-classes:calendarmessage' || l_lf
      || 'Content-Type: text/calendar;' || l_lf
      || '  method=REQUEST;' || l_lf
      || '  name="meeting.ics"' || l_lf
      || 'Content-Transfer-Encoding: 8bit' || l_lf
      || l_lf
      || p_body_ical || l_lf
      || l_lf
      || '------_=_NextPart--';
            
   l_connection := utl_smtp.open_connection(l_mail_serv, l_mail_port);
   utl_smtp.helo(l_connection, l_mail_serv);
   utl_smtp.mail(l_connection, p_from);
   utl_smtp.rcpt(l_connection, p_to);
   utl_smtp.data(l_connection, l_msg_body);
   utl_smtp.quit(l_connection);
   
END send_ical_email;

-- Create a page process similar to the following that fires 
-- when the submit button is pressed (this will vary depending on step 3): 

DECLARE

   l_ical_event VARCHAR2(32767);

BEGIN

   l_ical_event := ical_event(
      p_start_date      => TO_DATE(:PXX_START_DATE || :PXX_START_TIME,'DD-MON-YYYYHH:MIPM')
    , p_end_date        => TO_DATE(:PXX_END_DATE || :PXX_END_TIME,'DD-MON-YYYYHH:MIPM')
    , p_summary         => :PXX_SUBJ
    , p_organizer_name  => :PXX_USER_NAME
    , p_organizer_email => :PXX_USER_EMAIL
   );

   send_ical_email( 
      p_to        => :PXX_TO_ADDRESS
    , p_from      => :PXX_USER_EMAIL
    , p_subj      => :PXX_SUBJ
    , p_body_html => :PXX_BODY_HTML 
    , p_body_ical => l_ical_event
   );
   
END;

That should do it. Submit the page to send the request.