Turn off automatic addition of sender's certificates to Microsoft Outlook contacts

Disables the automatic creation and update of contact information with the sender's certificate attached to the opened email.

If this setting is not configured or disabled, then the sender's certificates are automatically added to the Microsoft Outlook contacts

Supported on: At least Windows Vista SP1

Registry HiveHKEY_LOCAL_MACHINE
Registry PathSOFTWARE\Policies\HID Global\ActivClient\CertificateRegistration\Outlook
Value NameAutoContactAddOff
Value TypeREG_DWORD
Enabled Value1
Disabled Value0

hidglobal.activclient.admx

Administrative Templates (Computers)