.ics file attachment being received as plain text message by outlook

Hi,
I am using microsoft outlook 2003 email client. When I am trying to
send an .ics file as part of the email generated from another
application to myself, this email when opened with Outlook has an .ics
attachment as desired, which can then be clicked on to become a
calendar object to be accepted/declined. But when I am trying to send
it to external users( their email client is outlook 2003 as well -
with or without versions sp1/sp2) it is being read as a plain text
message by their outlook. I am trying to understand as to why its
working for me while its not for the external users. What should done
in order for the external users to see this as an .ics attachment
which can be clicked on to become a calendar object? Any suggestions
please?
Thanks,
Mayuri

On Sep 24, 7:15 pm, "
wrote:
Hi,
I am using microsoft outlook 2003 email client. When I am trying to
send an .ics file as part of the email generated from another
application to myself, this email when opened with Outlook has an .ics
attachment as desired, which can then be clicked on to become a
calendar object to be accepted/declined. But when I am trying to send
it to external users( their email client is outlook 2003 as well -
with or without versions sp1/sp2) it is being read as a plain text
message by their outlook. I am trying to understand as to why its
working for me while its not for the external users. What should done
in order for the external users to see this as an .ics attachment
which can be clicked on to become a calendar object? Any suggestions
please?
Thanks,
Mayuri

For more information:
the plain-text message consists of:
BEGIN:VCALENDAR
PRODID:-//Microsoft Corporation//Outlook MIMEDIR//EN
VERSION:2.0
METHOD:REQUEST
BEGIN:VEVENT
DTSTAMP:20070924T220650Z
DTSTART:20070930T110000
DTEND:20070930T190000
SUMMARY:Test email
ORGANIZER;ROLE=CHAIR;PARTSTAT=ACCEPTED;RSVP=FALSE:
ATTENDEE;ROLE=REQ-PARTICIPANT;PARTSTAT=NEEDS-

SEQUENCE:0
UID:1131_1190689610000
DESCRIPTION:Single Vs. Plural\nMing\, if you get this as an attachment
please let me know via email. Did it open and go to your Outlook?
LOCATION:
PRIORITY:5
CLASS:PUBLIC
END:VEVENT
END:VCALENDAR