Hello Expertise,

We are running Exchange 2013. Few clients are using MS Office 2010 with active sync. From last couple of days there are getting an issue with their address book. Users' local address book is automatically changing according to Global address book. Users use their local address book as their personal reference as well. Please guide how to stop this ?

Thanks,

Hi Manoj,

Do you have deploy manual sync GAL to Outlook contacts, or sync GAL to ActiveSync device?
We can disable ActiveSync device, then we can validate what the problem is.

I find an similar thread about your question, for your reference:
https://social.technet.microsoft.com/Forums/en-US/b7b06db0-a6fa-4d84-ae23-ad96110611f7/how-to-block-syncing-personal-phone-contacts

Automatic updates of contacts enabled by default as a feature of social connector in outlook. To change the setting in Outlook 2010, View->People->Account Settings->Settings button and change the update option from Update without prompting to Prompt before update or Never update.

Group policy will help for bulk operation in the following section of GPO:
Outlook > Outlook Social Connector->Block Global Address List synchronization.

HKCU\Software\Policies\Microsoft\office\outlook\socialconnector
 DWORD: disablecontactgalsync
 Value: 1 (no sync)

Thanks