When troubleshooting mail items or folders that fail to synchronize support will ask for advanced logs to further troubleshoot.
Please use the below steps to enable this level of logging.
Stop ArchiveTools Folder Sync service
Go to installation directory. Default is C:\Program Files(x86)\Archivetools\Folder Sync
Open ArchiveAcceleratorSynchservice.exe.config in Notepad or other text editor.
Locate the following line.
Change the value to True as shown below.
Save and close file.
Start service and run sync on affected users.
Gather resulting logs for review
Note: This setting should be reversed by repeating these steps to change the value back to false in order to avoid using unnecessary disk space.