I'd like my web site generated invitations to mimic the behavior of those generated by Outlook itself. Specifically, when I send an invitation I'd like Outlook to mark the calendar item as TENTATIVE until accepted, and then OOF when accepted.
This is accomplished by Outlook itself via the setting of various X-MICROSOFT-CDO extensions to the VEVENT shown below in an example captured from Outlook:
X-MICROSOFT-CDO-APPT-SEQUENCE:0
X-MICROSOFT-CDO-OWNERAPPTID:-2105038887
X-MICROSOFT-CDO-BUSYSTATUS:TENTATIVE
X-MICROSOFT-CDO-INTENDEDSTATUS:OOF
X-MICROSOFT-CDO-ALLDAYEVENT:FALSE
X-MICROSOFT-CDO-IMPORTANCE:1
X-MICROSOFT-CDO-INSTTYPE:0
I've therefore attempted to set the two that appeared germane:
X-MICROSOFT-CDO-BUSYSTATUS:TENTATIVE
X-MICROSOFT-CDO-INTENDEDSTATUS:OOF
But my experience has been that although the Outlook meeting busy status is set to Tentative upon the receipt of the invitation, upon user Acceptance the status changes to BUSY rather than OOF as desired.
Is this not possible in standard SMTP?
Ideas?