After completing an Exchange to Google migration, users may notice a new folder in the destination called "Sync Issues".
The Sync Issues folder will often contain other subfolders such as Conflicts, Local Failures or Server Failures and all were created by the Exchange server, but generally hidden from the user. As these folders are seen by CloudM Migrate as regular mail folders, they are migrated as such and so become visible to migrated users.
These folders are generated by Exchange when historically there has been a synchronization problem between Outlook and Exchange, such as a connectivity problem, and the error has been logged in the local mailbox. Generally these folders can be deleted by the user post migration (and will be displayed in Gmail as labels and nested labels).