Version 3.5

Category: Operation, Version 3.0, Version 3.5, Version 4.x

If you want to exit SimpleSYN if Outlook is closed, follow these steps:

  1. Right-click on the SimpleSYN icon in the Windows notification area and choose “Exit”
  2. Close any Outlook window
  3. Open the SimpleSYN Add-In configuration file with a text editor like notepad. The configuration file can be found in:
    • Windows: C:\Users\[User name]\AppData\Local\SimpleSYN\\[Outlook profile name].addin.config
  4. Add the following code in the section between <appSettings> and </appSettings>:
    <!-- SimpleSYN is exited when Outlook is being closed. -->
    <add key="AutoExitSimpleSyn" value="true" />
    <!-- SimpleSYN is started if the Add-In is being loaded. -->
    <add key="AutoStartSimpleSyn" value="true" />
  5. Open Outlook again.

Category: Troubleshooting, Version 2.0, Version 2.1, Version 3.0, Version 3.5, Version 4.x

The message "destination folder was not found" appears if the top folder level in Outlook (eg "Personal folders") has been named differently on the SimpleSYN client and SimpleSYN server. In this case, SimpleSYN can not assign the destination folders automatically because no new PST files are created by SimpleSYN.

Click on the "Select a different target folder" link and select the folder where you want to sync.

Alternatively, you can name the highest folder level identically on all computers in advance.

Category: General, Version 3.0, Version 3.5, Version 4.x

Press on your server computer inside of SimpleSYN’s main window once the “Alt” key to open the main menu and choose the menu item “View > State Properties.

If you open the state database properties (Tab “General”) on the server, do you see any old client that is not synchronized anymore (you can see this from the last synchronization date)? 

If yes, please click on this client and click on “remove”. This will delete the status for the selected client will make some space available in the status database.

Category: General, Version 3.0, Version 3.5, Version 4.x

You should not synchronize IMAP email folders with SimpleSYN. IMAP folders are server based and automatically synchronized on all your computers. If you synchronize the same folders with SimpleSYN, it can lead to duplicated mails because two synchronization methods are interfering.

As IMAP cannot be used to synchronize appointments, tasks, contacts and notes, it is safe to synchronize those items with SimpleSYN.

Therefore make sure no email folders (i.e inbox) are selected on the SimpleSYN client in the “synchronization settings”. Also make sure no more email folders are listed in “Status -> pending synchronization”. If there is a folder listed here, right-click it and click “Do not synchronize”.

Category: General, Version 2.0, Version 2.1, Version 3.0, Version 3.5, Version 4.x

No, all of these devices are not supported by SimpleSYN.

SimpleSYN synchronizes Outlook installations with each other; a computer running Windows Vista (32bit/64bit), Windows 7 (32bit/64bit), Windows 8 (32bit/64bit) or Windows 10 (32bit/64bit) is essential.

If you wish to synchronize Outlook on your iPhone, Windows Phone or Android device, please contact the manufacturer of your device.

Category: General, Version 3.0, Version 3.5, Version 4.x

SimpleSYN Standard is fully compatible with the Business Version. You can only synchronize over a local network with the standard version, however.

Please note: The SimpleSYN server has to be in the same local network as the client.

Further note: The Configuration Wizard in the standard version cannot establish a connection with the SimpleSYN server if the SimpleSYN server is configured for synchronization via the Internet.

Category: Operation, Version 3.0, Version 3.5, Version 4.x

To call up the Configuration Wizard again, please follow these steps:

  1. Open the SimpleSYN user interface
  2. Press the “Alt“ key to show the SimpleSYN menu 
  3. In the menu under “Help” activate the entry “Show Configuration Wizard on next startup“
  4. Exit SimpleSYN. To do so right-click on the SimpleSYN symbol in the Windows system tray and choose “Exit”

The next time SimpleSYN is opened the configuration window will be displayed again.

Category: General, Version 2.0, Version 2.1, Version 3.0, Version 3.5, Version 4.x

Provided you have made changes to the default settings of the color categories, you will have to manually set up the list of color categories (formerly main category list) identically on all computers. The category list is not synchronized by SimpleSYN. The assigned categories in the items, however, are kept and synchronized by SimpleSYN.

Category: Installation, Version 3.5, Version 4.x

SimpleSYN requires an active internet connection for its operation. The internet connection is required to connect to a central server operated by SimpleSYN. This server is used to help in the establishment of a direct connection between the SimpleSYN server and SimpleSYN client. Only data required for establishing the connection is transferred via this central server. After establishing an connection, SimpleSYN uses the best connectivity available.

If SimpleSYN Business is used to synchronize via the Internet and it is impossible to create a direct connection between SimpleSYN server and SimpleSYN client, e.g. because of Firewalls NAT or Routers are blocking the direct connection, SimpleSYN uses a relay server as a last resort. This relay server allows SimpleSYN to communicate even if only outgoing traffic is allowed from your networks.

In either case the connection between SimpleSYN will always  use an SSL/TLS encryption respectively.

Your Outlook data is never transferred in clear-text nor stored permanently on our Internet servers (no Cloud).

Note: Proxy-Servers are not supported by SimpleSYN. SimpleSYN must communicate with our servers located at

SimpleSYN requires the following outbound TCP connections:

9235, 9236,
9235, 9236
49152 – 59152

Category: Operation, Version 3.5, Version 4.x

When using the automatic synchronization it is also possible to synchronize all Outlook® subfolders automatically. The Outlook® subfolders will use the same synchronization direction and settings as their parent folder. Changes to the folder hierarchy below a selected folder are being synchronized.

Changes of the selected parent folder are not automatically synchronized. If a selected parent folder is being moved or deleted, the synchronization of this folder and all of its children will stop. Adjust the synchronization settings

Category: Operation, Version 2.0, Version 2.1, Version 3.0, Version 3.5, Version 4.x

If a computer is not reachable over network or Internet, then the synchronization is carried out as soon as the computer is back in the network or online and SimpleSYN has established a connection with the SimpleSYN server.

All Outlook items that were changed or created up to that point are automatically recognized and synchronized by SimpleSYN.

Category: Operation, Version 3.5, Version 4.x

If SimpleSYN is not run on one or more computers or if the computers are not connected via local network or Internet, synchronization conflicts can occur if:

  • an Outlook item is changed on multiple computers
  • an Outlook item is changed on one computer and deleted on another

SimpleSYN offers you several ways of manually resolving synchronization conflicts in the user interface under the menu point “Conflicts”. The overview lists all known conflicts. Double-click on an entry and specify in the next window how SimpleSYN should resolve the conflict. Here you have a choice of:

  • Use client item:
    uses the item from the client list, changes on the server computer are overwritten
  • Use server item:
    uses the item from the server list, changes on the client computer are overwritten
  • Copy item:
    the item is only copied and both items are saved. Please note that only the item is duplicated
  • Do not synchronize:
    the item is not synchronized. Both versions of the item are saved and treated equal. Please note: If one of the items is then changed the other item will be overwritten.

If the item is deleted on one of the computers you have the option of keeping the change or deleting the item.

Alternatively, you have the option of letting SimpleSYN resolve the conflicts automatically.