At first check the following:
If not check the following FAQ.
There are no files on our server if two computers were online.
Bring all computers simultaneously online, check whether the changes are propagated.
If a given computer doesn't download the stored data within 14 days, the change requests in its Store-and-Forward Inbox will be deleted from our server and must then be transferred directly between the computers of your SYNCING.NET "Sync Folders" or "Outlook Groups". In order to do this the computers must be online at the same time for as long as the transfer takes
Our background process "SyncingOlWatchService might be blocked by another application.
Please be sure to set your security application to allow SYNCING.NET full access rights. Although some applications allow SYNCING.NET to run with "low restrictions" this is not adequate. SYNCING.NET must be grated "full rights" or set as a "trusted application".
Please allow the executable files SyncService.exe, SyncingOLWatchService.exe and NotificationService.exe access to the firewall settings.
If a special folder is no longer synchronized, please try to remove this folder from the synchronization.
Visit details /Outlook folders / - and remove the folder then add the folder via the + again.
Maybe our background process (SyncingOlwatchService.exe) was stopped and changes not detected.
In this case simply repeat your changes, for example set the e-mails as read/unread in your inbox..
Then these changes will be transfered automatically.