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How to troubleshoot CodeTwo Outlook Sync »

Problem: You are experiencing issues with CodeTwo Outlook Sync. Solution: CodeTwo Outlook Sync is a freeware and we do not provide technical support for this software. You can find general information about the tool and a setup guide on the program’s homepage. We have also prepared a number of Knowledge Base articles and a helpful [...] (ID:655)

Drag and Drop not working in Outlook »

Problem: You are not able to copy or move any Outlook items by dragging and dropping. Solution: As far as we know, this is a software bug that occurs in all versions of Outlook, and it is not related to CodeTwo or any other third-party software. We have discovered a few solutions that may restore the drag & drop functionality in Outlook: [...] (ID:542)

Mobile phone numbers are displayed improperly »

Problem: The telephone numbers of contacts created in the desktop version of Outlook do not appear correctly on mobile devices, for example the + sign is missing. As a result, you cannot make calls to these contacts from your mobile device. Solution: This problem is directly related to the way Outlook processes contacts. Possible [...] (ID:541)

Error: There is no email program associated to perform the requested action »

Problem: You get the following error message (Fig. 1.): There is no email program associated to perform the requested action. Please install an email program or, if one is already installed, create an association in the Default Programs control panel. Fig. 1. The error window. Solution: This problem concerns various Outlook related [...] (ID:351)

Multiple unnecessary folders appear in Outlook folder tree »

Problem: In your mailbox, you see many folders named the file so that changes to the file will be reflected in your item, and these files cannot be removed (Fig. 1.). Fig. 1. Multiple copies of the same unwanted folder. Solution: If you started seeing multiple redundant folders in your Outlook folder tree, this is most likely caused [...] (ID:344)

Using CodeTwo software with Click-to-Run versions of Microsoft Outlook »

Problem: You are not able to install CodeTwo software and you receive the following error message: Outlook not detected or No supported version of Microsoft Outlook detected. Install Microsoft Outlook and retry. even though MS Outlook is installed on your machine. Solution: First of all, please check if your system configuration is [...] (ID:330)

Existing Outlook data file in a new mail profile »

Problem: How to use your existing Outlook information (like emails, calendars, contacts, etc.) in a new mail profile. Solution: Oftentimes problems with Outlook are caused by a corrupt mail profile. In such cases the best solution is to create a new mail profile, which does not necessarily mean that you will loose all your existing [...] (ID:257)

How to resolve connection error in CodeTwo Outlook Sync if the computers have the same name »

Problem: How to resolve connection error in CodeTwo Outlook Sync if the computers have the same name? Solution: When trying to connect from one installation of CodeTwo Outlook Sync to another you receive this error: Fig. 1. "You are trying to connect to your own (local) machine" error. You need to change the name of one of the computers [...] (ID:242)

The appointments or meeting requests synchronized by CodeTwo Outlook Sync are off/shifted in time »

Problem: If you synchronize calendars using CodeTwo Outlook Sync, the time of some appointments and meeting requests disappear. Solution: To start with, make sure the same Time Zone is configured on both machines in Control Panel > Clock, Language, and Region > Date and Time. If the Time Zone is set correctly on both machines, scan the [...] (ID:225)

What is C2Backupfolder folder used for by CodeTwo Outlook Sync »

Problem: C2Backupfolder appears in Microsoft Outlook. Solution: On installing CodeTwo Outlook Sync in your Microsoft Outlook, C2Backupfolder folder is added to the Personal Mailbox. This folder will be used as a dumpster - a folder that retains all items and folders that are dropped/removed from the current computer due to the [...] (ID:221)

How to synchronize CodeTwo Outlook Sync over the Internet »

Problem: You want to synchronize CodeTwo Outlook Sync over the internet. Solution: CodeTwo Outlook Sync is mainly a local network software although you can synchronize your computers over the Internet. If you discover that you cannot use the program over the Internet, you will still be able to use it in the office or at home. Even if [...] (ID:215)

How to replace a computer that is synchronized with CodeTwo Outlook Sync »

Problem: How to replace a machine which is synchronized with CodeTwo Outlook Sync. Solution: When you replace one of the computers that are synchronized using CodeTwo Outlook Sync, please make note of these safety tips. For the purpose of this KB article we will use the following computers: Computer #1 and Computer #2 are currently [...] (ID:214)

Text in synchronized items is not correctly displayed »

Problem The font in the items synchronized using CodeTwo Outlook Sync is different from the font in the original items. For example, question marks (???) or jibberish appear (Fig. 1.). Fig. 1. This is how synchronized items may look on the other machine. Solution In order to fix this issue, you need to: change the language settings in [...] (ID:209)

How to avoid duplication of messages in inboxes synchronized using CodeTwo Outlook Sync »

Problem: How to avoid duplication of messages in inboxes synchronized using CodeTwo Outlook Sync. Solution: If your inboxes are synchronized using CodeTwo Outlook Sync and you get duplicate instances of email messages, you need to check the settings of your email accounts in MS Outlook. Frequently, when you start using a new application [...] (ID:203)

How to avoid duplicates during first synchronization »

Problem: How to correctly prepare Microsoft Outlooks for the first synchronization in Outlook Sync so that duplicate items will not be created. Solution: The first synchronization in CodeTwo Outlook Sync is very important. If not performed correctly, it can result in both synchronized Outlooks cluttered with unwanted duplicate items. [...] (ID:198)

How to solve connectivity problems between computers that use CodeTwo Outlook Sync »

Problem: You experience connectivity problems between computers that use CodeTwo Outlook Sync. Solution: Communication problems with CodeTwo Outlook Sync are usually caused by network problems. As a result, it is not possible to create a connection between two machines. Most problems can be solved by following the hints below. Make sure [...] (ID:191)

How to reset CodeTwo Outlook Sync to out of the box state »

Problem: How to reset the installations of Outlook Sync to the initial state before the first synchronization. Solution: In order to restore CodeTwo Outlook Sync to the initial state, you need to access the folder in which the application registers the synchronization settings and stores data on the items that have already been synced. [...] (ID:183)

How to configure a Send-Only account in Outlook »

Problem: You want to create a Send-Only email account (from which mail is never downloaded) in Outlook. Solution: To exclude an email account from receiving emails in Outlook, you need to add this account as a new POP3 account in Outlook. Then you need to modify this account by setting a fake (non-existent) incoming mail server. Finally, [...] (ID:81)

FAQ | CodeTwo Outlook Sync »

Download for free Frequently Asked Questions for CodeTwo Outlook Sync

Synchronize Outlook data | CodeTwo Outlook Sync »

Download for free CodeTwo Outlook Sync enables you to sync Outlook calendars, contacts, tasks, emails, documents and any other Microsoft Outlook items between two computers in your local network. The application is very easy to use and the entire installation and configuration process shouldn't take longer than 5 minutes. Watch a short [...]

CodeTwo Outlook Sync version history »

Version history Version Date 16 Jan 2019 Changed: Updated the digital signature certificate. Version Date 14 Sep 2017 Fixed: Outlook Add-in would crash Outlook or make the synchronization process slower after installing the Creators Update for Windows 10. Changed: The program is now available for free. Version [...]

Introduction »

CodeTwo Outlook Sync is a smart tool for syncing Outlook between two machines. By using it, you can easily synchronize two PST files or selected Outlook folders between two machines within seconds. The program is extremely easy to install, and setup and requires no additional configuration in Outlook. Installation The installation is [...]

Choosing folders to synchronize »

CodeTwo Outlook Sync allows you to synchronize Outlook PST files between two machines. You can sync both default and non-default (user created, additional) folders in Outlook depending on the program's settings. Tip If you do not have CodeTwo Outlook Sync program opened, you can run it from Start Menu by opening the CodeTwo folder and [...]

Quick guide to creating a synchronization group »

After the installation of CodeTwo Outlook Sync is completed on both machines which Outlook data you want to synchronize, click Yes on the first screen of the Configuration wizard on either of the machines (Fig. 1.). It will trigger the window that lets you choose the remote machine involved in the synchronization process. Tip If [...]

How to uninstall CodeTwo Outlook Sync »

Removing CodeTwo Outlook Sync is as easy as uninstalling it from the Windows Control Panel: Go to your Windows Control Panel. Click on Programs and Features (or Add or Remove Programs in older Windows version). Find CodeTwo Outlook Sync on the list, right mouse click on it and choose Uninstall. Follow the uninstaller wizard instructions [...]

Choosing a remote machine »

In this step (Fig. 1.) you are supposed to choose a remote machine (a second computer) you want to synchronize Outlook data with. All accessible machines from your local network should be displayed in the list. You can either select the desired computer from the list or enter its name or IP address in the field provided and [...]

Advanced settings »

The Advanced Settings in CodeTwo Outlook Sync let you control how the Administration Panel will be launched, activate / deactivate the Autosync feature and manage the port used for communication between two machines included in the group of synchronization. To access the settings, click Advanced in the top program's Administration [...]

Choosing data synchronization type »

The data synchronization type determines the first synchronization cycle of the chosen Outlook folders between two machines. Furthermore, once the initial synchronization is configured, all later synchronization cycles will always be performed in a two-way direction. It means that if you change anything in one folder, the change is [...]

Choosing synchronization mode »

CodeTwo Outlook Sync has two modes for syncing Outlook data between computers: manual synchronization automatic synchronization Tip If you do not have CodeTwo Outlook Sync program opened, you can run it from Start Menu by opening the CodeTwo folder and choosing Outlook Sync. Please also check if there is an Outlook Sync icon in [...]

Licensing »

The use of CodeTwo Outlook Sync is free of charge. For more information, read our End User License Agreement. Updating to the free version If you use any previous (paid) version of the software and want to update it to the free version, you need to download and install the current version from the product's Download page.

Supported platforms and requirements »

The table below shows the list of operating systems on which the program can be installed, Outlook versions supported and rights required to install the program installation: OS installation Outlook versions supported Installation rights required Windows 10 Windows 8.1 Windows 8 Windows 7 Windows Vista Windows XP (SP3) [...]

Installation process »

CodeTwo Outlook Sync can be installed on any machine regardless of its version. The installation process needs to be performed by a local administrator. Learn more about supported platforms and system requirements Note that as the program is designed to synchronize Outlook data between two machines, you need to run the program's [...]

Log files »

CodeTwo Outlook Sync generates log files. They are all kept within the standard Windows user's settings folder in the %appdata% folder. Viewing log files If you ever need to view log files, you can manually browse the Outlook Sync subfolder of the CodeTwo folder within your %appdata%. To do that: Open Windows Explorer. Copy the [...]

Installation »

The subarticles of this article include essential information required to install the program in your environment. By navigating between the below-listed sections, you will learn about: Installation process - information about the setup of the program. How to update or upgrade and what is the difference. Reinstall or move to a [...]

Reinstall or move to a different machine »

Sometimes you may need to reinstall the program or even to move it to a different computer. See below how to do that. Reinstallation Reinstallation of the software is rarely required. However, it may be recommended, for example when you accidentally remove some of the installation files or Windows Update or some third-party software [...]

How to update or upgrade and what is the difference »

The version number The program version is always visible at the very top of the main window of the program. It consists of 4 numbers separated by dots, e.g., following the pattern below: [major].[minor].[maintenance].[build] which mean the following: [major] - the first figure is the major version number and it changes rarely, [...]

Feedback »

Your feedback is very important to us. It has continuously helped us develop better applications and we strongly encourage you to send us your concerns and suggestions about new and existing features. Your opinion shapes new functionalities and drives changes in the forthcoming versions of our software. To share your opinion, please [...]

How to install and configure the program?

CodeTwo Outlook Sync needs to be installed individually on two machines that you want to synchronize with each other. The installation and configuration are very quick in easy. Download the installer from CodeTwo's website, run it and follow the wizard. 

How many computers can I synchronize?

CodeTwo Outlook Sync lets you synchronize Outlook data between two computers via local network.

Which Windows versions are supported?

Can I synchronize different versions of Outlook?


CodeTwo Outlook Sync lets you can synchronize different versions of Outlook even in a mixed environment. The program supports Outlook 2016, 2013, 2010, and 2007.

Do I need to be connected to the Internet to synchronize data?

No, you don't have to be connected to the Internet to sync Outlook data between two machines using CodeTwo Outlook Sync. The program works in a local network.

Is it possible to sync data in real time?

Yes. To sync data in real time, you need to switch the Autosync option on. This option is turned off by default. 

How do I use Autosync?

CodeTwo Outlook Sync has the Autosync option which lets you synchronize data automatically in the background. By default, the Autosync feature is switched off to let you fully control the flow of data between your two PCs.

Once Autosync is on, whenever you make any change in the Outlook folder that is synchronized with its mirror folder on the second machine, the synchronization process takes place immediately.

If Autosync is off, whenever you make any change in the Outlook folder that is synchronized with its mirror folder on the second machine, the synchronization will not take place until you click the Sync button in the program's administration panel.

To switch Autosync on and off, click the Advanced button in the program's top menu and select the Autosync checkbox.

Does the program synchronize folders after I close it?

When you close CodeTwo Outlook Sync, it is only minimized to your system tray and it still runs in the background. If you have the Autosync option switched on, the program will automatically synchronize your data when needed.

By going to the Advanced options, you can unselect the Always minimize to tray when closing the program window option so that the program is always being closed when you click the X button in the top-right corner of the program's window. 

Does the program synchronize my data when I'm offline?

No, it doesn't. But all changes made in your Outlook folders can be synchronized with the other machine when the other user or you reconnect to your local network.

How can I synchronize subfolders?


To synchronize subfolders, click the Sync Options button in the top program's menu and then select subfolders you want to synchronize. 

How to avoid duplication of items during the initial sync?

Please read the following KB article to learn how to avoid duplication of items during the initial sync.

Why can't I change the synchronization type once the program has been configured?

You can only select the synchronization type before the first sync (you can keep data from both PCs, from the other PC, or from your PC only). After the first synchronization being complete, all selected folders are equal. In other words, all selected folders will contain the same set of items (folder 1 will contain items from folder 2, and folder 2 will contain items from folder 1). Whenever you change anything in one of the folders, all changes will be reflected in the mirror folder on another machine as well. 

How to uninstall the program?

To uninstall CodeTwo Outlook Sync, go to Windows Control Panel, Programs and Features, right-click CodeTwo Outlook Sync, select Uninstall and complete the uninstaller wizard.