.net – Sending Outlook meeting requests without accept/decline option


I am sending an Outlook meeting request with my .NET-program using the following as a source:
Sending Outlook meeting requests without Outlook?
This worked well for me, but I still have one problem/question.

If I send an invitation directly with Outlook I have the possibility to define that I DONT want an answer (accept, decline, ..) from the invited people. So if the invited people open my mail they dont see accept, decline… buttons.

I want this behavior also if I send auto-generated mails with my .NET-program. Is there an option to deactive the answer-feature programmatically? So that receivers DONT see accept, decline… buttons if they open my auto-generated mails?

I already tried to set RSVP = False, DISALLOW-COUNTER = True:


I saved two ICS-Files with Outlook – one with answer enabled and one with answer disabled. The above two lines were the only different ones, but it doesn't work in my generated message. If I open the mail it still shows the accept, decline, … buttons. Any idea?

Best Solution

I believe you are talking about Outlook's "Request Responses" option. When that is unchecked, Outlook generates .ics files with RSVP=FALSE for all attendees. When the attendee receives this, they will still see Accept, Tentative, Decline buttons, but these buttons won't send a response, they will simply determine how or if this invitation is added to their own calendar.

If "Request Responses" is checked then RSVP=TRUE is used for all attendees which will cause their Accept/Tentative/Decline buttons to also show options for Send the Response Now, Do Not Send a Response (this is equivalent to what happens when Request Responses wasn't checked), and Edit the Response before Sending.

Related Question