Message ID in permanenturl changes for same items when using webdav RRS feed

  • Question

  • We have a client who uses Exchange 2007, but we have no control or sight of the servers.

    Our software uses webdav to retrieve a copy of the appointments on the server for a given set of users, and along with the appointment information, we keep track of the permanenturl to act as a key between systems for the item.

    Last week we had reports that our system was creating duplicates, and after investigating, we found that the permanenturl for two identical items were slightly different - specifically the messageID portion of the url was different, as in the example below:


    My question is, what can cause the messageID to change, and does this mean that the uri is not a consistent key?

    Any insight or help will be very useful.

    Wednesday, January 30, 2013 10:52 AM