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OsaSync will be discontinued in 2018.
Registering, license extension or subscription renewal is not possible anymore.
Technical support is still available until the end of your subscription period.
OsaSync will continue to run, also after your subscription period has ended.

Our website will be discontinued in May 2018. Our technical support and faq pages will still be available on

We recommend SimpleSYN as an alternative for OsaSync.
Itís cheaper then OsaSync and the company offers a discount of 25% for OsaSync customers. SimpleSYN can be tested 30 days for free.
Use the coupon code OsaSync during the order process (25% off).

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Getting Started with OsaSync PRO

Start syncing your first Outlook folder in 3 easy steps:

  1. Download and install OsaSync
  2. Configure OsaSync
  3. Synchronize a folder in Outlook

1. Download and install OsaSync

  • Download OsaSync from In this example we use Outlook 2013 so we download the OsaSync version for Outlook 2013:
    osasync download from the website
  • Clicking the Download Now button will prompt you to save the file OsaSync2013setup.exe.
  • After the download has finished open the folder in which the download has been installed. In firefox you can open the containing folder by right-clicking the downloaded file and choosing Open containing folder from the context menu:
    open containing folder

  •  Right-click the file OsaSync2013setup.exe and click Run as Administrator:

    run as administrator
    This starts the installation wizard.

  • OsaSync for Outlook 2013 requires two additional software installations: the Microsoft .Net Framework 4.0 and the Visual Studio Tools for Office runtime program. If one or both programs are not yet present on your computer the OsaSync installation wizard will prompt you to download and install these additions first:
    vsto tools for office download
    Click install to start the download. After the download has finished you will be prompted to accept the Microsoft license agreement. After agreeing click Install to start the installation. Once the additional software has been installed the OsaSync installation wizard will start:
    start osasync installation
  • Click Next and accept the Licence agreement on the next page. Click Next again until the wizard has finished. OsaSync has been installed in the
    C:\program files (x86)\OsaSync2013 folder

2. Configure OsaSync

OsaSync has to know with which computers you want to sync. OsaSync works by exchanging small temporary files between the synced computers. Therefor OsaSync has to know where to save those files and where to read the files from other computers. By configuring OsaSync we tell OsaSync where it has to save and read those files.

OsaSync can be configured in 3 modes: Cloud mode, Client-Server mode or Peer-to-Peer mode. In Cloud mode and in Client-Server mode all computers are using the same folder for exchanging the temporary OsaSync files: the OsaServer folder. In Client-Server mode this OsaServer folder is created on one computer in the lokal network to which all computers have access. In Cloud mode the OsaServer folder is created inside a shared folder in Dropbox, Onedrive, Google Drive or other (free) Cloud service. The Dropbox (or Onedrive etc) software synchronizes this folder to all other computers. For OsaSync the OsaServer folder in the Dropbox folder acts like a central folder in the network to which all computers have access. This is the most easy way of configuring OsaSync. It's fast, easy, reliable and secure so we will configure OsaSync now in Cloud mode. If you don't want to use Cloud mode you can configure OsaSync in Client-Server or in Peer-to-Peer mode. For detailed step-by-step instructions in how to configure OsaSync in Client-Server mode or in Peer-to-Peer mode please see our previous gettingstarted page.

 Configure OsaSync by running the OsaSync connection wizard.

  • Start Outlook. OsaSync will show a message telling you that no computers are configured yet. That is what we are about to do so click ok.
  • Click the OSASYNC tab and click the Options button:
    options button in the osasync menu
  • On the Options window click the button Run connection wizard:
    options windows
  • The OsaSync connection wizards opens in a new window. Click Next
    strart connection wizard
  • Now we choose how we are going to configure OsaSync. We choose Cloud mode (Recommended):
    configuration in cloud mode

    In this example we use our free Dropbox account. We could have also used a free Microsoft Onedrive or a free Google Drive account.
    If you have no Cloud service account yet you can get one now. Go to and sign up for a fee account. You can choose the Basic account type, it's free and more than sufficient for OsaSync. The Dropbox app will be downloaded to your computer. After installing this app you will have a Dropbox folder in your lokal folders on your computer. In this folder you can start creating other folders and sharing folders with others. Here's an example of the lokal Dropbox folder with a shared folder called Shared with Ron, shown in Windows Explorer:
    dropbbox folders in Windows explorer
  • Continue with the OsaSync connection wizard by clicking Next.
  • We can skip the next window Alternative computer name unless we are working with 2 or more users on the same computer. Click Next
  • In the Select folder window we have to navigate to the Dropbox folder:
    select osaserver folder
    Navigate by double clicking the folders. If you do not know where to find your Dropbox folder locate your Dropbox folder in Windows Explorer, select your shared folder and click in the address bar beneath the menu: 

    The address bar will now show the actual directory structure of the Dropbox folder. Here it is C:\Users\Hella\Dropbox\Shared with Ron. Now we can navigate to this folder in the connection wizard Select folder window:
    dropbox folder in the connection wizard
  • Click the Create OsaServer folder button. OsaSync will create this folder in the Dropbox folder.
    When your are going to run the OsaSync connection wizard on other computers the OsaServer folder will already be there because it has been synchronized by Dropbox. In that case select the OsaServer folder and click Next.
  • That's it. You have configured OsaSync on this computer:
    wizard ready
  • Before you can start synchronizing folders in Outlook you first have to install and configure OsaSync on at least one other computer. So repeat the above steps on the other computers.
    OsaSync saves the computer info in a small file called CnfComputers.txt on the OsaServer folder. On the second computer WAIT until this CnfComputers.txt file has been synced by Dropbox before you run the connection wizard on that computer. You can check the CnfComputers.txt (double click to open the file) to see if the line with the first computer name is in the file. Otherwise a new CnfComputers.txt file will be created that will overwrite the file on the first computer.

    In his example we have also ran the OsaSync connection wizard on computer VAITA-DELL. This computer is now listed in the computers box on the OsaSync options window:
    computers on the options window

    We can now start syncing folders in Outlook

3. Synchronize a folder in Outlook

Before we start synchronizing our first folder it is a good idea to make a backup of the .pst file in which Outlook stores all data. Here's how to do this.

A second thing to note is when you work with more than ONE top level folder in Outlook (e.g. Personal folders and Archive folders), OsaSync requires the names of the top level folders in which you want to synchronize folders to be the same on your other computers. E.g. if you want to sync your Contacts folder in a top level folder called Personal folders Hella with another computer on which the top level folder is called Personal folders, you first have to rename Personal folders Hella to Personal folders. Here's how to do this.

Let's start synchronizing the Contacts folder. There is no difference in syncing a Contacts folder or a Calendar; Tasks, Notes or E-mail folder so we could have chosen another folder type for this example. However if you want to sync the Calendar folder then you can also take a look at our Calendar synchronization page that explains three Calendar syncing scenarios.

OsaSync keeps all items in a folder in sync after a folder has been prepared for synchronization. This preparation has to be done only once and on only one computer. After this preparation OsaSync takes care of synchronizing all changes without any required action from your side.

The synchronization process merges the contents of the selected folder during the synchronization process if this folder already exists on the target computer. If the folder does not yet exist on the target computer then OsaSync will create the folder. In this example we synchronize the default Contacts folder and this folder exists on the other computer so OsaSync will merge the contents of both Contacts folders.

  • Select the Contacts folder in the Outlook folder list:

  • Click Properties in the OsaSync ribbon menu:

  •  Click the button Start synchronizing this folder...

  • The OsaSync folder synchronization wizard starts:

    If you do not want to merge the Contact folders on both computers you can use an alternative name, e.g. Ron's contacts. The other computer will create a new Contacts folder called Ron's contacts. In this way the user on the other computer can clearly distinguish between contacts originating from this computer and his own contacts.

    In this example we want OsaSync to merge both Contacts folders so we don't need an alternative name and click Next
  • Select the computers to sync with. In this example there is only one other computer so we make sure to select that computer name and click Next

  • In this wizard step we can indicate that the folder on the target computer should be Read-Only. We do not want that and click Next

  • Now the wizards starts the process called folder synchronization preparation. All contact data is copied in temporary files to the OsaServer folder. When the other computer checks for changes it will import these temporay files and create contacts it doesn't yet have.

  • When all data has been copied a summery is shown. You can see the number of items that have been succesfully prepared for syncing.

  • Clicking Next shows the Ready window. Click Finish to close this wizard.

  • To complete the sync process the prepared sync data has to be imported on the other computer. This will happen automatically when the time period for checking the other computers for changes has elapsed or when we choose check for changes on other computers from the OsaSync menu. On the other computer OsaSync will now perform two consecutive steps:
    1. Importing all contacts that have been prepared by the source computer.
      For each contact to import OsaSync checks if this contact is already present in the folder. If so then the contact will not be imported (and gets the same unique OsaSync ID as the contact on the source computer).
      OsaSync matches a contact as the same contact as on the source computer if the following contact properties are the same:
      - first name
      - last name
      - company
      - email address

      OsaSync will show the next progress window during this import phase of sync data from computer LENOVO-PCK:

    2. Merging the contents of the folder by looking for contacts that are not present on the source computer. These contacts will be copied to the other computers.
      When the source computer LENOVO-PCK has imported the contatcs that where found during merging, the Contacs folder will contain the same number of contacts.

    The synchronization process for the Contacts folder is ready. From now on OsaSync will automatically keep this folder in sync. No further action from your side is required.


These synchronization steps should NOT be repeated for this same folder on the other computers! This process has to run from ONE computer only (there can be an exception to this rule if you use alternative folder names). 


  • In this example we have configured OsaSync in Cloud mode. Cloud mode is recommened by Vaita because it is easy, fast and secure. If however you do not want to use a Cloud service you can configure OsaSync in Client-Server mode or in Peer-to-Peer mode. We recommends Client-Server mode if you do not want to configure OsaSync in Cloud mode and have 3 or more computers. Configuring computers in C/S mode is more easy than Peer-to-Peer mode and some OsaSync processes will run faster. You can still choose C/S mode if the central computer is sometimes not running. OsaSync on the other computers will than run in Local Mode.

    For a detailed step-by-step instruction in how to configure OsaSync in Client-Server mode or in Peer-to-Peer mode please see our previous gettingstarted page.

  • You can also start the prepare folders for synchronziation process by clicking the Prepare folders for synchronization button in the OsaSync ribbon menu.

    The prepare folders for synchronization wizard will then offer the possibility to sync in advanced mode. In order to improve the performance when synchronizing multiple large folders, the advanced syncing mode has been created. In advanced mode OsaSync will NOT create temporary data files for the target computers but only assign a unique OsaSync ID to each item in each folder being synced. This runs much faster (between 4 and 5 minutes per 1000 items) . A big difference with normal syncing mode is that in advanced mode you have to manually copy the .pst file with the synced folders to the target computers after the wizard has finished.. This means you cannot merge the contents of two different .pst files and your starting point for synchronization will be the same .pst file on all computers. A scenario where this can be feasible is syncing your desktop with your laptop. On our FAQ page you can read a step-by-step instruction for syncing in advanced mode.

  • Preparing a calendar, tasks, notes or e-mail folder for synchronization is exactly the same as described above for the Contacts folder. OsaSync will also merge the contents of the synced folder if the synced already exists on the target computers. While merging OsaSync assumes an item is identical when the following item properties match:

    • Calendar folders: appointment start date; end date; subject and location.
    • Tasks folders: task start date; due date; subject and status.
    • Notes folders: note subject; contents and color.
    • E-mail folders: emails received: internet message ID. Emails sent: subject and time send. Unsent emails: subject only.

    To read more on Calendar syncing see the Calendar synchronization page.

    For differences in how OsaSync handles calendar, tasks, notes and e-mail items compared to contact items please read: Does OsaSync PRO handle the other Outlook items in the same way as it does contacts? on the FAQ page.

  • If OsaSync encounters problems during the creation or importing of the synchronization data read The sync.log file indicates errors during importing sync data on the technical support page

  • If you want to resynchronize a folder then please read How to prepare a folder for synchronization again on the technical support page



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