Another meeting update: do I have to respond?

My name is Angela and I am a programmability writer for Outlook. Outlook 2007 was the first version of Outlook I worked on. The part I like about my work is to describe to people how a feature in an application works. I think, I am probably not the last person to learn about the feature, and if I can channel my passion to document the feature and help someone else interested to learn about it, that’s makes my day more meaningful!

I’d like to talk about a feature that I recently documented in the Outlook 2007 Auxiliary Reference: meeting requests as informational updates and full updates. Even though this feature already exists in the user interface, I was able to learn about the complete picture from our own Outlook Product Team.

In Outlook 20007, meeting organizers can send updates to prior meeting requests. Recipients receive these updates in the form of full updates or informational updates. The significance is that a full update requires the recipient to explicitly respond to it, because Outlook ignores any previous responses, whereas an informational update does not require the recipient to respond to it.

So when does a recipient receive an update as a full update? Outlook uses the reason for the update to decide what type it should be: any changes related to time information, such as the date, time, time zones, or recurrence will generate a full update. But if a recipient has not responded to an initial meeting request, and if the organizer sends a subsequent update for any reason, such as changing the location of the meeting, on that recipient’s computer, Outlook will consider the initial meeting request as out-of-date, and the update is a full update, regardless of the cause of the update.

A recipient receives an update as an informational update in each of the following scenarios. This assumes that the recipient has already responded to the initial meeting request.

  • The organizer changes the location of a prior meeting request.
  • The organizer adds a new attendee to the meeting request and chooses to send an update to the existing attendees.
  • The organizer removes an attendee from the meeting request and chooses to send an update to the remaining attendees.
  • The organizer changes the subject or body to the meeting request and chooses to send an update to the attendees.

Programmatically, how does one identify the update status of a meeting request item in Outlook? There is a named property, dispidMeetingType, that is exposed on meeting request items. When Outlook receives a meeting request item, Outlook creates and sets that property for the item. Possible values for the property are:





Outlook has not set this property for the message.


Message is a new meeting request.


Message is a full update of a prior meeting request.


Message is an informational update of a prior meeting request.


Message is out-of-date and a more recent update has been sent to the recipient.


Message is a copy of a meeting request, or a copy of an update of a prior meeting request received by the principal recipient. The original meeting request or the update has been sent to a delegate of the principal.


You might have a question about the delegated status of a meeting request item. To drive you to discover more about the Outlook 2007 Auxiliary Reference, I am suggesting you to continue reading here: About Meeting Requests as Informational Updates and Full Updates and the dispidMeetingType property.

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