The other day I was troubleshooting an issue with an ActiveSync device that had duplicate contacts. Now, this is not a new issue, there a quite a few articles on TechNet that describe possible issues that could related to duplicate contacts.
However, In this particular case, the issue seems to have been related to Lync 2013 client. When looking at the duplicate contact on the ActiveSync device, I noticed that the contact description had a message saying:
This contact was added from Lync 2013
At this point, its clear what’s causing the duplicate contact issue, so what is this and how do we fix it? If we check Microsoft Outlook 2010/2013, we can see under contacts that we have a new contacts folder called Lync Contacts. Now this folder will only appear if you have Lync client installed. In the Lync Contacts folder, we’ll notice right away that we have duplicate contacts.
Here we have a couple of options of how we want to fix this.
- Clear the Lync Contacts folder and re-synchronized ActiveSync contacts (Issue might comeback)
- If you’re on Lync Server/Client 2010 you can disable Lync contact sync under personal options of the Lync Client
- If you’re on Lync Server/Client 2013, we have to run a powershell command that disables the sync
- Create a filter within the Lync Contacts with the “lyncignore” (I have not tested this)
In my case, the infrastructure is Lync 2013 so I had to run a powershell command to disable this feature. The following is the command that needs to be run:
Set-CsClientPolicy Global -EnableExchangeContactSync $false
Once the command is run, the Lync Contacts folder will need to be cleared and ActiveSync device needs to be re-synchronized with the contacts. Lync will now stop synchronizing your contacts with Microsoft Outlook.
In some environments you might want to give this a careful thought before disabling this feature, however in my case, this is not really used so it’s safe to disable it. It is also just as easy to enable it.