this is a pretty well known issue i think, but i was unable to figure out how to solve it. I am trying to send a cancellation message for an appointment as described here: http://groups.google.com/group/microsoft.public.exchange2000.development/msg/23eaa8d3283756da?dmode=source&hl=en It is a well known piece of code and I haven't changed it except for the neccessary parts and the uid I retrieve from the original appointment. I am able to send the cancellation message, and outlook even displays the "cancellation message" icon next to the item. However, when opening it I don't have the "remove from calendar" option, but the regular "accept, tentative, decline" buttons, as if outlook identifies this as a new appointment. When using OWA it does show the "remove from calendar" button and does correlate the calender message to the original appointment. Any ideas will be highly apreciated! ;) btw - this also happens with indendantsoft's webdav .net... Ehud Rosenberg.
I will answer myself ;) It took a while, but what was needed was adding <mapi:appstateflags>7</mapi:appstateflags> and making sure responseRequested is 0. The wonders of Webdav development...
