Category: Installation, SimpleSYN Mobile, Version 2.x / 3.x

SimpleSYN Mobile supports the following versions of Microsoft ® Windows ® and Outlook ®.

Requirements for the Windows PC hosting the installation:

• Microsoft® Windows®
  • Windows^® 11 (x86/x64)
  • Windows^® 10, version 1909 or newer (x86/x64)
• Microsoft® Outlook ®
  • Microsoft/Office 365^® mit Outlook^® (x86/x64)
  • Outlook^® 2024, 2021, 2019, 2016 (x86/x64)

Important: The classic Outlook for Windows is supported - not the new Outlook app

For the device you want to synchronize, the following requirements must be met:

• Supports all smartphones and tablet computers based on:
  • Apple iOS, iPadOS version 12 or later 
  • Android version 8 and later

Please note:

• An active internet connection is required for synchronization.
• All participating devices must be turned on at the same time for synchronization, as your Outlook data is not stored in the cloud.

Category: Installation, Version 6.x

SimpleSYN supports the following versions of Microsoft Outlook:

• Microsoft/Office 365^® with Outlook^® (x86/x64)
• Outlook^® 2024 (x86/x64)
• Outlook^® 2021 (x86/x64)
• Outlook^® 2019 (x86/x64)
• Outlook® 2016 (x86/x64)
• Outlook® 2013 (x86/x64)

SimpleSYN also works in mixed environments.

Important:
The classic Outlook for Windows is supported, not the new Outlook app.

Category: Troubleshooting, Version 5.x, Version 6.x

The behavior can occur if Outlook was installed in a different bit version than the previous version during the new installation. In this case, the bit versions of Outlook and SimpleSYN no longer match and SimpleSYN can no longer be started.

Uninstall SimpleSYN under the Windows control panel (or under "Apps") and then reinstall SimpleSYN.

If the behavior occurs again afterwards, then install SimpleSYN in the correct bit version as follows:

1. First find out in which bit version (32 bit or 64 bit) Outlook was installed after the reinstallation.
   To do this, open Outlook and click on "File > Office Account > About Outlook". You can see the bit version behind the version number.
2. Uninstall SimpleSYN from “Windows > Settings > Apps > Installed Apps”.
3. Then download SimpleSYN and navigate to the directory where the "SimpleSYN.exe" file (for the standard version) or "SimpleSYN_Business.exe" file (for the business version) is located (e.g. on the desktop or in the download folder) .
4. In this directory, press and hold the „shift" key on the keyboard and right click in a free area and select " Open PowerShell window here " from the context menu.

5. After that, the Windows PowerShell window will open.

   Now type in the following command and press the ENTER key.

   Note: Pay attention to the correct spelling. There is no space at the beginning of the command between ".\".

   With the standard version:

   When you have installed Outlook in 32-Bit, use the following command:
   .\SimpleSYN.exe Platform=x86

   When you have installed Outlook in 64-Bit, use the following command:
   .\SimpleSYN.exe Platform=x64

   With the business version:

   When you have installed Outlook in 32-Bit, use the following command:
   .\SimpleSYN_business.exe Platform=x86

   When you have installed Outlook in 64-Bit, use the following command:
   .\SimpleSYN_business.exe Platform=x64

6. You can then install SimpleSYN. After the installation, SimpleSYN is started correctly again.

Category: Troubleshooting, Version 2.x / 3.x

You have probably installed the new major version 3. The version number is displayed in the user interface under “Information.” If you have installed version 3 but prefer to stay with version 2, please follow these steps:

1. Uninstall Version 3:
   Go to Windows > Settings > Apps > Installed Apps, find SimpleSYN Mobile Version 3 in the list of installed programs, and uninstall it.
2. Reinstall Version 2:
   Download and install the previous version 2 from the following link:
   https://www.simplesyn.net/Media/Default/Downloads/Mobile/2.8.13611/SimpleSYN_Mobile.exe

After that, everything should work as usual again.

Note:

With a lifetime license, there are no additional monthly/annual costs. The license entitles you to unlimited use of the licensed version (e.g., version 2.0). Minor updates (e.g., version 2.0 to version 2.0.1, etc.) are free. Upgrades to new major versions (e.g., version 2.x to version 3) are subject to a fee, but are of course optional. Subscription licenses include both minor updates and upgrades to new major versions.

With a lifetime license, new major versions are not installed automatically. Instead, they are displayed in the user interface under "Information." This is how we inform customers with a lifetime license that a new major version is available. Lifetime license customers have the opportunity to test the new major version and can manually initiate the download from the user interface.

If you prefer to stay with version 2, you can hide the upgrade notification:

Open the update dialog and click “Do not show this upgrade again” to stop receiving further notifications about version 3.

Category: Troubleshooting, Version 5.x, Version 6.x

Duplicate e-mails can occur on an POP3 account, when e-mails from more than one computer being synchronized are requested from the e-mail server. This is the case if the Outlook function “Leave copy of messages on the server” was activated in a POP3 E-mail account.

The tricky here is that SimpleSYN cannot force Outlook to stop downloading an email a second time on another computer. If the first computer downloads the mail from the email server and it gets synchronized before the second computer downloads it, Outlook cannot detect that the email is already there. The second computer will than download the email from the email server and you got a duplicate. As the first email is also already synchronized, SimpleSYN assumes that the second download is intentional and synchronizes this copy too.

In this case deactivate the Outlook function “Leave copy of messages on the server” so as not to save e-mails in your mail server and download them repeatedly.

To deactivate this function follow these steps:

1. Open Outlook
2. Open the Backstage area by clicking on “File“
3. In the category “Information” click on “Account Settings” and “Add or Remove Accounts…”
4. Highlight the POP3 E-mail account in question and click on “Change“
5. Click on “More Settings“
6. In the tab “Advanced” deactivate the check box “Leave copy of messages on the server“
7. Confirm the changes by clicking “OK“
8. Click on “Next“ and then on “Finish“

If you are using a current version of Outlook:

1. Open Outlook
2. Open the Backstage area by clicking "File"
3. In the "Information" category, click "Account Settings" and then "Add or Remove Accounts..."
4. Select the affected POP3 email account and click "Change"
5. In the next dialog, uncheck the "Leave a copy of all messages on the server" checkbox
6. Confirm the changes by clicking "Next"

Category: Troubleshooting, Version 5.x, Version 6.x

If you have made changes to the Outlook default color categories, you must ensure that the color category list (formerly the "Main Category List") is manually configured identically on all PCs. SimpleSYN does not automatically synchronize this list. The categories assigned to the items are retained and correctly synchronized by SimpleSYN.

Starting with version 6, the "Add new categories to the main category list" function is available.

If this option is enabled, SimpleSYN checks during synchronization whether all categories used in the items are also present in the main category list. If a category is missing, it is automatically added to the list with a default color. You can then manually adjust the color to ensure a consistent display across all devices.

Category: Troubleshooting, Version 5.x, Version 6.x

Here's what to do if the folder list in the synchronization settings remains empty and no folders are displayed:

1. Completely close Outlook and SimpleSYN on the affected PC.
2. Then restart both programs.

If the issue persists, please check the following points:

Set the correct Outlook version:

• Open SimpleSYN.
• Go to “Options” > “Advanced Options”.
• Under “Outlook Version”, select the version you actually have installed (e.g., Outlook 2021 or Outlook 2016).
• Save the settings and restart SimpleSYN.

Check permissions:

• Make sure that both Outlook and SimpleSYN are started without administrator rights.

Verify the Outlook profile:

• In SimpleSYN, open the main menu > Options.
• Ensure that the same Outlook profile is used as when starting Outlook.

Category: Troubleshooting, Version 2.x / 3.x

With a lifetime license, new major versions are not installed automatically. Instead, they are displayed in the user interface under "Information." This is how we inform customers with a lifetime license that a new major version is available. Lifetime license customers have the opportunity to test the new major version and can manually initiate the download from the user interface.

Would you like to stay with version 2?

Please first uninstall version 3 via Windows > Settings > Apps > Installed Apps.

Afterwards, you can download and reinstall version 2 from the following page:
https://www.simplesyn.net/Media/Default/Downloads/Mobile/2.8.13611/SimpleSYN_Mobile.exe

After that, everything should work as usual again.

If you want to stay with version 2, you can also deactivate the upgrade notice as follows:

Simply click “Do not show this upgrade again” in the update dialog to stop receiving further upgrade notifications.

Some more information about the licenses:

With a lifetime license, there are no additional monthly/annual costs. The license entitles you to unlimited use of the licensed version (e.g., version 2.0). Minor updates (e.g., version 2.0 to version 2.0.1, etc.) are free. Upgrades to new major versions (e.g., version 2.x to version 3) are subject to a fee, but are of course optional. Subscription licenses include both minor updates and upgrades to new major versions.

Category: Troubleshooting, Version 5.x, Version 6.x

If you receive this message, please follow these steps:

Check the Outlook version in SimpleSYN:

• Open the SimpleSYN main menu on this PC.
• Go to “Options” > “Advanced Options”.
• Under “Outlook Version”, select the version you actually have installed (e.g., Outlook 2021).
• Save the settings and restart SimpleSYN.

Reinstall SimpleSYN:

• If the issue persists, uninstall SimpleSYN:
  • Open “Windows > Settings > Apps > Installed Apps”.
  • Find SimpleSYN in the list and uninstall it.
• Then reinstall SimpleSYN.

Repair your Office installation:

• If the problem still occurs after reinstalling SimpleSYN, repair your Office installation:
  • Again, go to “Windows > Settings > Apps > Installed Apps”.
  • Find Microsoft Office, click “Modify”, and choose the “Online Repair” option (not the quick repair).
  • Follow the on-screen instructions.

Category: Troubleshooting, Version 5.x, Version 6.x

How to activate the Outlook add-in in SimpleSYN:

1. Open the SimpleSYN main window on your PC.
2. Go to “Options” and then to “Advanced Options.”
3. Check the box for “Enable Outlook Add-In.”
4. Save the settings.
5. Then restart SimpleSYN.

Additional note:
Open Outlook and go to “File” > “Slow and deactivated COM Add-Ins.”
Check if the SimpleSYN add-in has been disabled there. If so, please re-enable it.

Category: Troubleshooting, Version 2.x / 3.x

In the SimpleSYN Mobile application on the Windows PC, under “Options > advanced options”, change the value for the “http port”, e.g. instead of “9238” > “9240”.

Then click on the link “Click here to update Windows configuration” to adjust the changed configuration.

Restart SimpleSYN Mobile and create the SimpleSYN Mobile account on the smartphone again.

Category: Troubleshooting, SimpleSYN Mobile, Version 2.x / 3.x

If you set up the SimpleSYN Mobile account on the mobile device and made a mistake when entering the e-mail address or the password, there will be no error message with the old Android versions, but the settings are incomplete and synchronization cannot take place.

Make sure that "Server" displays a longer string of numbers and letters, followed by ".simplesyn.app".

If only"simplesyn.app" is displayed in "Server", you probably have typed in a wrong email address or password. In this case, tap the back arrow and check the email address and password details.

Category: Troubleshooting, Version 5.x, Version 6.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: Installation, Troubleshooting, Version 6.x

This message indicates that SimpleSYN cannot be installed on your computer because you are probably using an ARM processor.

SimpleSYN is only compatible with Windows 11 or 10 on computers with classic x86 or x64 processor architectures (Intel or AMD). Installation on ARM-based systems is not supported.

Category: Operation, Version 5.x, Version 6.x

Your Outlook data is not stored online in the cloud. Therefore, all computers must be turned on at the same time for synchronization to occur – this also applies to the Business version of SimpleSYN.

If a computer is currently unavailable (e.g., turned off or without an internet connection), synchronization will automatically resume as soon as the computer is back online and SimpleSYN can establish a connection to the main computer (server).

All changes or newly created Outlook items will be detected and automatically synchronized.

Note for the Business Edition:
SimpleSYN can be run as a Windows service. This means that no user login is required when Windows starts – synchronization can take place even without an active user session.

Category: Operation, Version 5.x, Version 6.x

To automatically close SimpleSYN when Outlook is closed and to start it again automatically when Outlook is started, make the following settings:

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\4.0.0.0\[Outlook profile name].addin.config
   
   At Version 5:
   C:\Users\[User name]\AppData\Local\SimpleSYN\5.0.0.0\[Outlook profile name].addin.config
   
   At Version 6:
   C:\Users\[User name]\AppData\Local\SimpleSYN\Add-In\6.0.0.0\[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: SimpleSYN Mobile, Version 2.x / 3.x

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: SimpleSYN Mobile, Version 2.x / 3.x

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: Operation, Troubleshooting, SimpleSYN Mobile, Version 2.x / 3.x

The earliest date that the Google Calendar app can display is January 1, 1970. The appointments were synchronized correctly, but cannot be displayed in the app.

For birthdays, we recommend storing them in contacts. Older appointments can also be added there and the calendar app displays them correctly.

Category: Installation, Version 5.x, Version 6.x, Version 2.x / 3.x

You will need to have administrator rights for the installation of SimpleSYN.

Category: Purchase, Version 5.x, Version 6.x, Version 2.x / 3.x

Please contact our Support, with details on purchase date and order number.

Category: Operation, Version 5.x, Version 6.x

With the SimpleSYN Business version, you can not only synchronize Outlook locally, but also synchronize Outlook between separate networks over the Internet. The SimpleSYN Standard version supports synchronization only within the local network.

Category: Installation, Version 5.x, Version 6.x

SimpleSYN is a Client-/Server application. In your SimpleSYN network one PC must be configured as a server. The SimpleSYN server must be authorized in the Windows Firewall and/or Desktop firewall.

Please make sure that SimpleSYN is allowed in your personal firewall.

SimpleSYN must communicate with our servers located at services.simplesyn.net.

SimpleSYN requires the following outbound TCP connections.

Category: Installation, Version 5.x, Version 6.x

An active internet connection is required for synchronization using SimpleSYN Business and SimpleSYN Standard.
SimpleSYN uses this connection to contact a central server operated by SimpleSYN, which facilitates the connection between the SimpleSYN server and the SimpleSYN client.

Only the information necessary to establish the connection is transmitted — your Outlook data is never stored in the cloud. Afterward, SimpleSYN attempts to establish a direct connection between the participating installations. The best available connection method is selected automatically.

If a computer using the SimpleSYN Business version is to be synchronized over the internet, but a direct connection between the SimpleSYN server and client cannot be established — for example, due to firewalls, routers, or NAT — SimpleSYN will use a relay server as a last resort. This allows communication even in networks where only outbound traffic is permitted.

All communication is always encrypted using SSL or TLS. Outlook data is never transmitted in plain text or permanently stored on our servers — it is only forwarded directly and securely.

Note: 
Proxy server support is available starting with SimpleSYN version 5. For older versions, access to our servers at services.simplesyn.net must be explicitly allowed.

SimpleSYN requires the following outbound TCP connections.

Category: General, Installation, Version 5.x, Version 6.x

In the standard configuration (both in the Business and Standard versions), SimpleSYN requires an active Internet connection. SimpleSYN uses this connection to contact a central server operated by SimpleSYN, which facilitates the connection between the SimpleSYN server and the SimpleSYN client.

Only the information necessary to establish the connection is transmitted — your Outlook data is never stored in the cloud. Afterward, SimpleSYN attempts to establish a direct connection between the participating installations. The best available connection method is selected automatically.

All communication is always encrypted using SSL or TLS. Outlook data is never transmitted in plain text or permanently stored on our servers — it is only forwarded directly and securely.

Why does the Standard version also use this method?
Since most users today have an internet flat rate, we decided to use the central server in the Standard version as well — however, with the limitation that the connection is only established within the local network.

Using SimpleSYN without an Internet Connection

If you would like to use SimpleSYN without an internet connection or without our central server, then there is the option of changing the connection configuration so that our central server is no longer necessary.

Important:
This setting is primarily intended for the Standard version. In the Business version, synchronization will only work within the same local network after switching to this mode — synchronization over the internet will no longer be possible.

How to activate the custom connection (from version 5):

1. Open the SimpleSYN main window.
2. Go to Options > Advanced Options.
3. On all PCs (server and clients), enable the option “Custom connection mode”.
4. On each client, enter the computer name or the static IP address of the SimpleSYN server in the field “Custom server name/address”.