Category: Operation, Version 4.x

E-mail folders (for example, Inbox) of IMAP accounts are not displayed by default in the synchronization settings.

An IMAP account is server-based and keeps your e-mail automatically in sync.An additional synchronization of the e-folders is therefore no longer necessary.

In the SimpleSYN main window under Options> Advanced Options you can activate the option "Show IMAP folder" as required. However, if you enable this feature and select Email Folders to sync, duplicate emails may appear after syncing.

Therefore, we recommend that you do not synchronize your e-mail folders with SimpleSYN!

Of course, since an IMAP account can only keep email folders up-to-date, you can still sync all other folders such as calendars, contacts, tasks, and notes with SimpleSYN.

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

9235, 9236,
9235, 9236
49152 – 59152

Category: Troubleshooting, Version 2.0, Version 2.1, Version 3.0, Version 3.5, Version 4.x, Version 5.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“

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

E-Mail folders of IMAP accounts (eg Inbox or sent objects) are hidden in the "Synchronization settings", since IMAP already keeps the e-mail folders in sync (IMAP is server-based).

You can use SimpleSYN for all other folders such as calendars, contacts, tasks, notes, etc.

If you also want to synchronize e-mail folders with SimpleSYN, then use a POP3 account on all PCs.

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

The SimpleSYN Business Version 4 installs a Windows service. If the option "Start as Windows service" is activated in the 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: 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

Please check the following things:

  1. Make sure, that you have not restricted the folders on your computers. You find this function on your client computer in the main window > synchronization settings > Advanced client settings. On your server computer you can find this function on the “main window > synchronization settings. Under “Available Folders” make sure that you have activated some folders
  2. Make sure neither Outlook nor SimpleSYN is started with administrator rights.
  3. Check if SimpleSYN and Outlook are using the same Outlook profile. You can see the Outlook profil in SimpleSYN in the main window > Options
  4. Make sure SimpleSYN is not started with compatibility settings enabled. To check this, right click on the SimpleSYN shortcut and select “Properties”. Click on “Compatibility” and remove tick in the checkbox “Run this program in compatibility mode”. It is possible, that this setting was somehow enabled during the Windows 10 upgrade.
  5. If you have multiple Outlook versions installed concurrently, select the right version in SimpleSYN under Options -> Advanced Options

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

You`ll need a license per computer you want to synchronize. 

For example: If you wish to synchronize Outlook between your laptop and your desktop computer, you will need two licenses. If you want to synchronize 3 computers, you`ll need 3 licenses, etc. If you want to use SimpleSYN on a terminal server with different users, you need a license for each user.

  • A SimpleSYN standard license costs 19.95 € per computer (including 19% VAT)
  • A SimpleSYN business license costs 34.95 € euros per computer (including 19% VAT

Ask about our discounts for school, university students, teachers and multiple licenses

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

You purchase the desired license quantity on the website and initiate the order transaction, then follow the instructions. The payment process is handled by our sales partner Digital River GmbH (share-it!).

Ask about our discounts for school, university students, teachers and multiple licenses. 



Share-it - Digital River GmbH
Scheidtweilerstr. 4
50933 Köln
Tel.: +49 221 31088-30
Fax: +49 221 31088-99

Category: Operation, Version 3.5, Version 4.x, Version 5.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 3.0, Version 3.5, Version 4.x, Version 5.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, Version 5.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 2.0, Version 2.1, Version 3.0, Version 3.5, Version 4.x, Version 5.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: Support Services, Version 2.0, Version 2.1, Version 3.0, Version 3.5, Version 4.x, Version 5.x

Any questions can be posed to our Support under the e-mail address support@simplesyn.net or you can use the Support Form. Before you turn to our Support, however, please make sure that:

  • you have the newest version of SimpleSYN installed
  • you have taken a look at the SimpleSYN user manual. A lot of common questions have already been addressed there

In emergencies you can reach our Support under the following telephone number:

Telephone: +49 511-53 46 22-4

We hope you will understand that we cannot always guarantee our availability by phone.