EWS : Lifetime of Synchronization State cookie

Question

I am using the SyncFolderItems operation to synchronize my calendar folder.

What is the lifetime of the Synchronization State cookie returned by the SyncFolderItems call?

If I use a 40-day old SyncState string (saved in the DB from an earlier call) in the SyncFolderItems Call, will I get back the 40 days worth of data? Or will that Sync State have expired?

Also, is SyncState string valid between different versions of Exchange server? (2007 and 2010) ?

Answer 1

Andy-

A 40-day old SyncState string should work, and you should get back the 40 days worth of data.

As for the SyncState string being valid between different versions, yes, it should be upwardly compatible. The string is marked with a version stamp and may be upgraded the first time it’s used against a new server version but should continue to work fine. The only caveat is that once used against a new server and the sync state has been upgraded, the updated sync state cannot be used against the old version.

-Mimi