Information
This policy setting controls whether Outlook downloads files attached to Internet Calendar appointments.
If you enable this policy setting, Outlook automatically downloads all Internet Calendar appointment attachments
If you disable or do not configure this policy setting, Outlook does not download attachments when retrieving Internet Calendar appointments. The recommended state for this setting is: Disabled.
Rationale:
Files attached to Internet Calendar appointments could contain malicious code that could be used to compromise a computer.
By default, Outlook does not download attachments when retrieving Internet Calendar appointments.
Solution
To implement the recommended configuration state, set the following Group Policy setting to Disabled.
User Configuration\Administrative Templates\Microsoft Outlook 2013\Account Settings\Internet Calendars\Automatically download attachments
Impact:
Disabling this setting enforces the default configuration in Outlook, and therefore is unlikely to cause usability issues for most users.