Category: Installation, Version 4.x, Version 5.x

You can easily upgrade Outlook (Office). The previous version does not need to be uninstalled. SimpleSYN automatically detects the new Outlook version.

Install Outlook in the same bit version as the previous version, either in 32-bit or 64-bit.

If you want to install Outlook in a different bit version than the previous version, first uninstall SimpleSYN and reinstall SimpleSYN after the Outlook update.

Category: Installation, Version 4.x, Version 5.x

SimpleSYN requires a unique configuration and a unique certificate for each PC.

SimpleSYN must be completely reset to one of the clients. Then SimpleSYN can be reinstalled and set up.

Follow these steps:

  • Uninstall SimpleSYN first under the Windows Control Panel "Programs / Features" or under Apps on Windows 10
  • Then enter the following line in Windows Explorer:
  • Find the folder SimpleSYN here and delete this folder.

Then delete the SimpleSYN certificate as follows:

  • Open the Internet Explorer
  • Go to "Internet Options"
  • Click the "Content" tab
  • Click on "Certificates"
  • In the next window under "Display name" search for the SimpleSYN entries, mark the respective entry and click on "Remove"

Then you can reinstall SimpleSYN and set it up again. The initial synchronization will be run once again.

Category: Troubleshooting, Version 4.x, Version 5.x

Open the SimpleSYN options > advanced options and under “Outlook version” select your current Outlook version (2016 or 2013).  Save the settings and restart SimpleSYN.

If the behavior still occurs:

  • Please uninstall SimpleSYN on this computer from the Windows control panel > program/features and install SimpleSYN once again

If the behavior still occurs:

Category: Troubleshooting, Version 4.x, Version 5.x

If SimpleSYN cannot establish a connection make sure the following is correct:

  1. Make sure SimpleSYN is installed and started on both the client and the server computer
  2. At least one computer has to be configured as SimpleSYN server and a second as SimpleSYN client
  3. Install the latest version of SimpleSYN on all computers that are to be synchronized
  4. Make sure you have an active internet connection on both computers
  5. Check whether the time is correctly set on both computers. Set the same time on both computers.


  1. Make sure the correct server has been selected on the SimpleSYN clients.
  2. Make sure the password has been entered correctly.

Category: Operation, Version 4.x, Version 5.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:

    At Version 4:
    C:\Users\[User name]\AppData\Local\SimpleSYN\\[Outlook profile name].addin.config

    At Version 5:
    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: Installation, Version 4.x

In that case, you probably have an Office 365 version from the Microsoft App Store installed.

Programs from the Microsoft App Store can not currently recognize SimpleSYN version 4 (these programs are isolated from the rest of the system). Office 365 version from the Microsoft App Store supports SimpleSYN version 5.

Please reinstall Outlook / Office at https://www.office.com/setup

Then everything should work and go through the installation.

Category: Operation, Version 4.x, Version 5.x

The SimpleSYN business version can be started by a Windows service. If the option "Start as Windows service" is activated in the advanced options, then SimpleSYN automatically starts in the background when the Windows starts, without a Windows user having to log on to the system.

The SimpleSYN standard version 4 and all older versions do not support Windows service. The synchronization takes place here only if a user is logged on to the computer and SimpleSYN is executed.

Category: Troubleshooting, Version 4.x, Version 5.x

Please make a Outlook repair installation on this computer. Please follow this instruction:

Important: choose a full online Outlook repair installation and NOT a quick repair.

Category: Version 1.0

If you want to sync multiple Outlook data files, create a separate user account for each Outlook data file. Multiple user accounts are also suitable for synchronizing different mobile devices (e.g. iPhone and iPad) with separate settings.

You can manage the user accounts individually and select which folders to synchronize for each user. Thus, it is possible to synchronize, e.g., on the iPhone only the Outlook calendar and on the iPad additionally to synchronize the contacts. 

Category: General, Version 5.x

A good start is always to remove items from the Outlook “Deleted Items” folder and also configure the SimpleSYN backup functionality to remove outdated items.

This can be done in SimpleSYN under “Options -> Advanced options -> Remove backed up items”. Here you can specify the period of time after which the items are to be permanently removed from the backup folder.

Category: Version 1.0

For setting up the synchronization on the device, a special SimpleSYN Mobile account of the type "Exchange ActiveSync" is created.

During the first synchronization, the data is synchronized from Outlook to the mobile device. Changes made in this account after the first synchronization are always synchronized by SimpleSYN Mobile to both sides (bidirectional).

E-mails, appointments and contacts that were saved on the mobile device before the first synchronization, i.e. that are not in the SimpleSYN account, are not synchronized to Outlook because they use different accounts. If you also want to keep this data up to date in the future, make sure that this data is also available in Outlook before the first synchronization.

Category: Version 1.0

There is usually no need to install an additional app on your mobile device. For setting up the synchronization on the device, a special SimpleSYN Mobile account of the type "Exchange ActiveSync" is created.

Before SimpleSYN Mobile can be used for synchronization, you must set up SimpleSYN Mobile once, configure the devices you want to synchronize and connect them to SimpleSYN Mobile.

The setup process therefore includes two steps:

  1. Installing and setting up the SimpleSYN Mobile software on your Windows ® PC with Outlook ® installed.
  2. The configuration on your devices (e.g. smartphone).

During setup on the PC, a SimpleSYN Mobile pseudo email address is automatically generated. The address has the ending @simplesyn.app and is required to establish a connection from your device.

You can find more information about the setup on this page.

Category: Troubleshooting, Version 5.x

Open the SimpleSYN main window> Options> advanced options on the PC.

Check the box next to "Enable Outlook Add-In" and save the page.

Then restart SimpleSYN.

Otherwise, check once in Outlook under File> Slow and deactivated COM add-ins whether in this area the add-in has been deactivated and reactivate the add-in if necessary.

Category: Version 1.0

On the Windows PC, the Outlook data file must be selected in the SimpleSYN Mobile main window under "Configuration" and here the "Contacts" and the "Calendar" must be selected for synchronization.

The SimpleSYN Mobile calendar or contacts must be selected on the Android device and the entry "Synchronize contacts" and "Synchronize calendar" must also be activated in the account settings for the SimpleSYN Mobile account (see example below).