2.2.16 [RFC5545] Section 3.2.12 Participation Status

V0023:

The specification describes the optional PARTSTAT parameter.

Microsoft Exchange Server 2007

Exchange 2007 only exports the PARTSTAT parameter for ATTENDEE ([MS-OXCICAL] section 2.1.3.1.1.20.2) properties in iCalendar objects with a METHOD ([MS-OXCICAL] section 2.1.3.1.1.1) of "REPLY" or "COUNTER". The possible values of this parameter are "DECLINED", "ACCEPTED", and "TENTATIVE".

On import, Exchange 2007 ignores all PARTSTAT parameters except those on ATTENDEE properties in iCalendar objects with a METHOD of "REPLY" or "COUNTER" (case-insensitive).

For iCalendar objects with a METHOD of "REPLY", Exchange 2007 fails to import the iCalendar object unless there is exactly one ATTENDEE property with a PARTSTAT parameter, and the value of the parameter is "ACCEPTED", "DECLINED", or "TENTATIVE" (case-insensitive).

For iCalendar objects with a METHOD of "COUNTER", Exchange 2007 fails to import the iCalendar object unless there is exactly one ATTENDEE property with a PARTSTAT parameter, and the value of the parameter is "ACCEPTED", "DECLINED", "TENTATIVE", or "NEEDS-ACTION" (case-insensitive).