Category: Installation, Version 6.x/7.x

SimpleSYN supports the following Windows^® systems and Outlook^® versions:

Microsoft^® Windows^®

• Windows^® 11 (x86/x64)

Microsoft^® Outlook^®

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

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

Please note:

• An active internet connection is required for synchronization (applies to SimpleSYN Business and Standard).
• All participating Windows PCs must be turned on at the same time for synchronization, as your Outlook data is not stored in the cloud.
• The Windows service is only available in the SimpleSYN Business version. In the SimpleSYN Standard version, a Windows user must be logged on to the computer for synchronization.
• Synchronization of external data sources (e.g. Google Calendar or iCloud) is not supported.

Category: Troubleshooting, Version 5.x, Version 6.x/7.x

If SimpleSYN (Standard or Business) suddenly doesn’t start and the icon is no longer visible in the Windows taskbar, this is usually caused by an issue accessing the “SimpleSYN.config” file.

Here’s how to fix it step by step:

1. Close Outlook if it’s currently running.

2. Open Windows Explorer and navigate to the following folder, depending on your SimpleSYN version:

   • Version 5:
     C:\Users\[Your Username]\AppData\Local\SimpleSYN\5.0.0.0
   • Version 6:
     C:\Users\[Your Username]\AppData\Local\SimpleSYN\6.0.0.0
   • Version 7:
     C:\Users\[Your Username]\AppData\Local\SimpleSYN\7.0.0.0

3. Locate the file named “SimpleSYN.config” in that folder.

4. Delete this file.

5. Restart SimpleSYN. The file will be automatically recreated.

After restarting, SimpleSYN should work normally again. You’ll just need to reactivate it once using your license file.

Don’t have your license file anymore?

No worries – simply contact the SimpleSYN Support Team to retrieve your license.

Category: Support Services, Version 5.x, Version 6.x/7.x

Yes, SimpleSYN is updated in irregular intervals (e.g. for Bugfixes).

All updates within the same main version (eg version 7.0 to version 7.0.1 etc.) are included. Major upgrades to new versions (eg version 6.x to version 7) are optional and available for an additional low price.

Category: Installation, Version 5.x, Version 6.x/7.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/7.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: Purchase, Version 5.x, Version 6.x/7.x

Licenses are offered as a one time payment. There are no additional costs per month/year. The license entitles you to use the licensed version (e.g. version 6.0). Minor updates within this version (eg version 6.0 to version 6.0.1 etc.) are included free of charge. Upgrading to a new major version (e.g., from version 6.x to version 7) is subject to a fee but is, of course, optional.

If you already own a license for SimpleSYN Version 5 or Version 6, you are eligible for a 20% discount when upgrading to Version 7 – for the same number of licenses.

Upgrade Pricing for Version 7:

• Standard Edition: 29.95  € per PC (incl. 19% VAT) – minus 20% discount
• Business Edition: 39.95 € per PC (incl. 19% VAT) – minus 20% discount

Free Upgrade:
All customers who purchased SimpleSYN Standard or Business Version 6 between February 1, 2026, and March 31, 2026, will receive a free upgrade to Version 7 in the same number of licenses purchased.

How to get your Upgrade:
Simply send us an email to support@simplesyn.net including your order number and purchase date.

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 15 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: Operation, Version 5.x, Version 6.x/7.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 5:
   C:\Users\[User name]\AppData\Local\SimpleSYN\5.0.0.0\[Outlook profile name].addin.config
   
   At Version 6 and Version 7:
   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.