Hello,
Virus and Spyware Protection includes a feature that is called Download Insight. Download Insight relies on reputation information to make detections. If you disable Insight lookups, Download Insight runs but cannot make detections. Other protection features, such as Insight Lookup and SONAR, use reputation information to make detections; however, those features can use other technologies to make detections.
Download Insight has the following dependencies:
-
Auto-Protect must be enabled
If you disable Auto-Protect, Download Insight cannot function even if Download Insight is enabled.
-
Insight lookups must be enabled
Symantec recommends that you keep the Insight lookups option enabled. If you disable the option, you disable Download Insight completely.
So, in case if you disable Download Insight, the clients would surely receive the Warning message.
Check this Article:
How Symantec Endpoint Protection protection features work together
http://www.symantec.com/docs/HOWTO55268
How Symantec Endpoint Protection uses reputation data to make decisions about files
http://www.symantec.com/docs/HOWTO55275
Hope that helps!!