[sync] Horde EAS: FolderIDs change after resync

[GMX]

Hello,

I run into a horde specific behavior, which I do not see with microsoft EAS or zpush. I am the developer of the TbSync EAS client for Thunderbird. 

If - for whatever reasons - i have to resync the folder hierachy by resetting the synkey to 0, i get back a complete new list of FolderIDs.

If the user has local changes in one of his folders, i no longer know, which folderID these changes belong to and have to drop them (which is bad). The only option i have is to identify the folder by its name, but that is not save as well.

Is there a specific reason, why horde is doing that? Can the horde user change that behavior in his horde options? Am I missing something else?

Thanks for your help
John