Google IS scanning your Gmail and admits it!

http://www.digitalspy.com/tech/news/a564741/google-clarifies-email-scanning-policy.html

Google has updated its terms of service to offer more transparency regarding its email-scanning practices. The web giant confirmed that Gmail messages are automatically scanned when content passes between its servers. Google has staunchly defended this policy, insisting that email scanning is necessary to provide tailored content and protect users against malware.